CA2863505C - Press-fit terminal and electronic component using the same - Google Patents

Abstract

There is provided press-fit terminal having excellent whisker resistance, low inserting force, high heat resistance, and is unlikely to cause shaving of plating when terminal is inserted into substrate. Terminal comprises: female terminal connection part provided at one side of attached part attachable to housing; and substrate connection part provided at other side and attached to substrate by press-fitting substrate connection part into through-hole formed in substrate. Substrate connection part has surface structure comprising: A layer formed as outermost surface layer and formed of Sn, In, or alloy thereof; B layer formed below A
layer and comprising Ag, Au, Pt, Pd, Ru, Rh, Os, Ir or any combination thereof; and C layer formed below B layer and comprising Ni, Cr, Mn, Fe, Co, Cu or any combination thereof.
Layers A, B and C have following respective thickness: 0.002 to 0.2 µm; 0.001 to 0.3 µm; and 0.05 µm or larger.

Description

[Document Name] Description [Title of Invention] PRESS-FIT TERMINAL AND ELECTRONIC
COMPONENT USING THE SAME
[Technical Field]
[0001]
The present invention relates to a press-fit terminal comprising: a female terminal connection part provided at one side of an attached part to be attached to a housing; and a substrate connection part provided at the other side and attached to a substrate by press-fitting the substrate connection part into a through-hole formed in the substrate, and an electronic component using the same.
[Background Art]

[0002]
A press-fit terminal is an acicular terminal having compressive elasticity, and is press-fitted into a through-hole formed in a substrate, to ensure a frictional force (retaining force), thereby being mechanically and electrically fixed to the substrate. A
copper-plated electrode portion is formed on an inner circumferential surface of a conventional through-hole.
The electrode portion contributes to a retaining force between the through-hole and a press-fit terminal pin. A

male connector (plug connector) is attached to the press-fit terminal fixed to the substrate, and is fitted to a female connector (receptacle connector), thereby establishing electrical connection. The surface of a terminal for the press-fit terminal is mainly subjected to Sn plating in order to improve a contact property with a through-hole of a connection substrate in light of lead free.
This press-fit terminal connects a connection terminal and a control substrate without performing conventional soldering. It is not assumed that the press-fit terminal once inserted into the through-hole is extracted from the through-hole again. Therefore, as a matter of course, a person cannot insert the terminal for the press-fit terminal into the through-hole with a hand.
For example, when the terminal for the press-fit terminal is inserted into the through-hole, a normal force of 6 to 7 kg (60 to 70 N) per terminal is required. A
significant pushing force is required in a connector subjected to molding, because 50 to 100 terminals are simultaneously used as the press-fit terminal.
For this reason, when the terminal for the press-fit terminal is inserted into the through-hole, the outer periphery of the press-fit terminal is subjected to a large welding pressure by the through-hole; comparatively soft Sn plating is shaven; and the shaven pieces are dispersed around, which disadvantageously causes short-

- 3 -circuit between the adjacent terminals depending on the case.
[0003]
By contrast, a press-fit terminal inserted into a conductive through-hole of a substrate in a press-fit state is described in Patent Literature 1. In the press-fit terminal, at least a substrate inserting portion of the press-fit terminal is subjected to tin plating with a thickness of 0.1 to 0.8 m, and the portion for which the tin plating is carried out is subjected to copper intermediate layer plating with a thickness of 0.5 to 1 m and nickel base plating with a thickness of 1 to 1.3 m, thereby to enable the suppression of the shaving of the tin plating.

[0004]
A press-fit terminal is described in Patent Literature 2. In the press-fit terminal, a base plating layer made of Ni or a Ni alloy is provided on the entire surface of a base material. A Cu-Sn alloy layer and a Sn layer are sequentially provided on the surface of the base plating layer of the female terminal connection part of the base material, or a Cu-Sn alloy layer and a Sn alloy layer are sequentially provided on the surface.
Alternatively, a Au alloy layer is provided on the surface. A Cu3Sn alloy layer and a Cu6Sn5 alloy layer are sequentially provided on the surface of the base plating layer of the substrate connection part of the base material, and Sn is not exposed on the surface of the Cu6Sn5 alloy layer. Thereby, the generation of shaving offscum of the Sn plating can be suppressed as compared with Patent Literature 1; and a synergistic effect obtained by providing the soft Sn layer or Sn alloy layer on the hard Cu-Sn alloy layer can improve a coefficient of friction to thereby weaken an inserting force when a terminal for press-fit is inserted into the through-hole.
[Citation List]
[Patent Literature]

[0005]
[Patent Literature 1]
Japanese Patent Laid-Open No. 2005-226089 [Patent Literature 2]
Japanese Patent Laid-Open No. 2010-262861 [Summary of Invention]

[0006]
However, in the technique described in Patent Literature 1, whiskers are generated in the mechanical/electrical connection part between the conductive through-hole of the substrate and the press-fit terminal; a sufficiently low inserting force cannot be acquired; the plating is shaven to thereby generate the shaving offscum; and a sufficiently high heat resistance cannot be acquired although a heat resistance has been required at 175 C in USACAR specification in recent years.
Also in the technique described in Patent Literature 2, a press-fit terminal is not achieved, which has an excellent whisker resistance and a low inserting force, is unlikely to cause shaving of plating when the press-fit terminal is inserted into a substrate, and has a high heat resistance.
Thus, the press-fit terminal subjected to the conventional Sn plating has problems of a whisker resistance, an inserting force, shaving of plating when the press-fit terminal is inserted into the substrate, and a heat resistance.
The present invention has been achieved to solve the above-mentioned problems, and an object thereof is to provide a press-fit terminal which has an excellent whisker resistance and a low inserting force, is unlikely to cause shaving of plating when the press-fit terminal is inserted into the substrate, and has a high heat resistance, and an electronic component using the same.

[0007]
The present inventors have found that in some embodiments of the present invention, a press-fit terminal which may have excellent whisker resistance and may have a low inserting force may be provided by using a metal material obtained by sequentially forming an A layer, a B layer, and a C layer formed at a predetermined thickness by using a predetermined metal from an outermost surface layer, and thereby a press-fit terminal which may be unlikely to cause shaving of plating when the press-fit terminal is inserted into a substrate, and may have a high heat resistance may be fabricated.
[00081 One aspect of the present invention completed based on the above finding is a press-fit terminal comprising:
a female terminal connection part provided at one side of an attached part to be attached to a housing; and a substrate connection part provided at the other side and attached to a substrate by press-fitting the substrate connection part into a through-hole formed in the substrate, wherein at least the substrate connection part has the surface structure described below, and the press-fit teLminal has an excellent whisker resistance; the surface structure comprises:
an A layer formed as an outermost surface layer and formed of Sn, In, or an alloy thereof;
a B layer formed below the A layer and constituted of one or two or more selected from the group consisting of Ag, Au, Pt, Pd, Ru, Rh, Os, and Ir; and a C layer formed below the B layer and constituted of one or two or more selected from the group consisting of Ni, Cr, Mn, Fe, Co, and Cu; wherein the A layer has a thickness of 0.002 to 0.2 gm;
the B layer has a thickness of 0.001 to 0.3 gm; and the C layer has a thickness of 0.05 gm or larger.
[0009]
Another aspect of the present invention is a press-fit terminal comprising: a female terminal connection part provided at one side of an attached part to be attached to a housing; and a substrate connection part provided at the other side and attached to a substrate by press-fitting the substrate connection part into a through-hole formed in the substrate, wherein at least the substrate connection part has the surface structure described below, and the press-fit terminal has a low inserting force; the surface structure comprises:
an A layer formed as an outermost surface layer and formed of Sn, In, or an alloy thereof;
a B layer formed below the A layer and constituted of one or two or more selected from the group consisting of Ag, Au, Pt, Pd, Ru, Rh, Os, and Ir; and a C layer formed below the B layer and constituted of one or two or more selected from the group consisting of Ni, Cr, Mn, Fe, Co, and Cu; wherein the A layer has a thickness of 0.002 to 0.2 gm;
the B layer has a thickness of 0.001 to 0.3 gm; and

- 8 -the C layer has a thickness of 0.05 pm or larger.
[0010]
Further another aspect of the present invention is a press-fit terminal comprising: a female terminal connection part provided at one side of an attached part to be attached to a housing; and a substrate connection part provided at the other side and attached to a substrate by press-fitting the substrate connection part into a through-hole formed in the substrate, wherein at least the substrate connection part has the surface structure described below, and the press-fit terminal is unlikely to cause shaving of plating when the press-fit terminal is inserted; the surface structure comprises:
an A layer formed as an outermost surface layer and formed of Sn, In, or an alloy thereof;
a B layer formed below the A layer and constituted of one or two or more selected from the group consisting of Ag, Au, Pt, Pd, Ru, Rh, Os, and Ir; and a C layer formed below the B layer and constituted of one or two or more selected from the group consisting of Ni, Cr, Mn, Fe, Co, and Cu; wherein the A layer has a thickness of 0.002 to 0.2 pm;
the B layer has a thickness of 0.001 to 0.3 pm; and the C layer has a thickness of 0.05 pm or larger.
[0011]
Further another aspect of the present invention is a press-fit terminal comprising: a female terminal

- 9 -connection part provided at one side of an attached part to be attached to a housing; and a substrate connection part provided at the other side and attached to a substrate by press-fitting the substrate connection part into a through-hole formed in the substrate, wherein at least the substrate connection part has the surface structure described below, and the press-fit terminal has an excellent heat resistance; the surface structure comprises:
an A layer formed as an outermost surface layer and formed of Sn, In, or an alloy thereof;
a B layer formed below the A layer and constituted of one or two or more selected from the group consisting of Ag, Au, Pt, Pd, Ru, Rh, Os, and Ir; and a C layer formed below the B layer and constituted of one or two or more selected from the group consisting of Ni, Cr, Mn, Fe, Co, and Cu; wherein the A layer has a thickness of 0.002 to 0.2 gm;
the B layer has a thickness of 0.001 to 0.3 gm; and the C layer has a thickness of 0.05 gm or larger.
[0012]
Further another aspect of the present invention is a press-fit terminal comprising: a female terminal connection part provided at one side of an attached part to be attached to a housing; and a substrate connection part provided at the other side and attached to a substrate by press-fitting the substrate connection part

- 10 -into a through-hole formed in the substrate, wherein at least the substrate connection part has the surface structure described below, and the press-fit terminal has an excellent whisker resistance; the surface structure comprises:
an A layer formed as an outermost surface layer and formed of Sn, In, or an alloy thereof;
a B layer formed below the A layer and constituted of one or two or more selected from the group consisting of Ag, Au, Pt, Pd, Ru, Rh, Os, and Ir; and a C layer formed below the B layer and constituted of one or two or more selected from the group consisting of Ni, Cr, Mn, Fe, Co, and Cu; wherein the A layer has a deposition amount of Sn, In of 1 to 150 g/cm2;
the B layer has a deposition amount of Ag, Au, Pt, Pd, Ru, Rh, Os, Ir of 1 to 330 g/cm2; and the C layer has a deposition amount of Ni, Cr, Mn, Fe, Co, Cu of 0.03 mg/cm2 or larger.
[0013]
Further another aspect of the present invention is a press-fit terminal comprising: a female terminal connection part provided at one side of an attached part to be attached to a housing; and a substrate connection part provided at the other side and attached to a substrate by press-fitting the substrate connection part into a through-hole formed in the substrate, wherein at

- 11 -least the substrate connection part has the surface structure described below, and the press-fit terminal has a low inserting force; the surface structure comprises:
an A layer formed as an outermost surface layer and formed of Sn, In, or an alloy thereof;
a B layer formed below the A layer and constituted of one or two or more selected from the group consisting of Ag, Au, Pt, Pd, Ru, Rh, Os, and Ir; and a C layer formed below the B layer and constituted of one or two or more selected from the group consisting of Ni, Cr, Mn, Fe, Co, and Cu; wherein the A layer has a deposition amount of Sn, In of 1 to 150 g/cm2;
the B layer has a deposition amount of Ag, Au, Pt, Pd, Ru, Rh, Os, Ir of 1 to 330 g/cm2; and the C layer has a deposition amount of Ni, Cr, Mn, Fe, Co, Cu of 0.03 mg/cm2 or larger.
[0014]
Further another aspect of the present invention is a press-fit terminal comprising: a female terminal connection part provided at one side of an attached part to be attached to a housing; and a substrate connection part provided at the other side and attached to a substrate by press-fitting the substrate connection part into a through-hole formed in the substrate, wherein at least the substrate connection part has the surface structure described below, and the press-fit terminal is

- 12 -unlikely to cause shaving of plating when the press-fit terminal is inserted; the surface structure comprises:
an A layer formed as an outermost surface layer and formed of Sn, In, or an alloy thereof;
a B layer formed below the A layer and constituted of one or two or more selected from the group consisting of Ag, Au, Pt, Pd, Ru, Rh, Os, and Ir; and a C layer formed below the B layer and constituted of one or two or more selected from the group consisting of Ni, Cr, Mn, Fe, Co, and Cu; wherein the A layer has a deposition amount of Sn, In of 1 to 150 g/cm2;
the B layer has a deposition amount of Ag, Au, Pt, Pd, Ru, Rh, Os, Ir of 1 to 330 pg/cm2; and the C layer has a deposition amount of Ni, Cr, Mn, Fe, Co, Cu of 0.03 mg/cm2 or larger.
[0015]
Further another aspect of the present invention is a press-fit terminal comprising: a female terminal connection part provided at one side of an attached part to be attached to a housing; and a substrate connection part provided at the other side and attached to a substrate by press-fitting the substrate connection part into a through-hole formed in the substrate, wherein at least the substrate connection part has the surface structure described below, and the press-fit terminal has

- 13 -an excellent heat resistance; the surface structure comprises:
an A layer formed as an outermost surface layer and formed of Sn, In, or an alloy thereof;
a B layer formed below the A layer and constituted of one or two or more selected from the group consisting of Ag, Au, Pt, Pd, Ru, Rh, Os, and Ir; and a C layer formed below the B layer and constituted of one or two or more selected from the group consisting of Ni, Cr, Mn, Fe, Co, and Cu; wherein the A layer has a deposition amount of Sn, In of 1 to 150 g/cm2;
the B layer has a deposition amount of Ag, Au, Pt, Pd, Ru, Rh, Os, Ir of 1 to 330 g/cm2; and the C layer has a deposition amount of Ni, Cr, Mn, Fe, Co, Cu of 0.03 mg/cm2 or larger.
[0016]
In one embodiment of the press-fit terminal according to the present invention, the A layer has an alloy composition comprising 50 mass% or more of Sn, In, or a total of Sn and In, and the other alloy component(s) comprising one or two or more metals selected from the group consisting of Ag, As, Au, Bi, Cd, Co, Cr, Cu, Fe, In, Mn, Mo, Ni, Pb, Sb, Sn, W, and Zn.
[0017]
In another embodiment of the press-fit terminal according to the present invention, the B layer has an

- 14 -alloy composition comprising 50 mass% or more of Ag, Au, Pt, Pd, Ru, Rh, Os, Ir, or a total of Ag, Au, Pt, Pd, Ru, Rh, Os, and Ir, and the other alloy component(s) comprising one or two or more metals selected from the group consisting of Ag, Au, Bi, Cd, Co, Cu, Fe, In, Ir, Mn, Mo, Ni, Pb, Pd, Pt, Rh, Ru, Sb, Se, Sn, W, Tl, and Zn.
[0018]
In further another embodiment of the press-fit terminal according to the present invention, the C layer has an alloy composition comprising 50 mass% or more of a total of Ni, Cr, Mn, Fe, Co, and Cu, and further comprising one or two or more selected from the group consisting of B, P, Sn, and Zn.
[0019]
In further another embodiment of the press-fit terminal according to the present invention, a Vickers hardness as measured from the surface of the A layer is Hv100 or higher.
[0020]
In further another embodiment of the press-fit terminal according to the present invention, the A layer has a surface indentation hardness of 1,000 MPa or higher, the indentation hardness being a hardness acquired by measuring an impression made on the surface of the A
layer by a load of 0.1 mN in an ultrafine hardness test.
[0021]

- 15 -In further another embodiment of the press-fit terminal according to the present invention, a Vickers hardness as measured from the surface of the A layer is Hv1,000 or lower, and the press-fit terminal has high bending workability.
[0022]
In further another embodiment of the press-fit terminal according to the present invention, the A layer has a surface indentation hardness of 10,000 MPa or lower, the indentation hardness being a hardness acquired by measuring an impression made on the surface of the A
layer by a load of 0.1 mN in an ultrafine hardness test, and the press-fit terminal has high bending workability.
[0023]
In further another embodiment of the press-fit terminal according to the present invention, the A layer has a surface arithmetic average height (Ra) of 0.1 gm or lower.
[0024]
In further another embodiment of the press-fit terminal according to the present invention, the A layer has a surface maximum height (Rz) of 1 gm or lower.
[0025]
In further another embodiment of the press-fit terminal according to the present invention, the A layer has a surface reflection density of 0.3 or higher.
[0026]

- 16 -In further another embodiment of the press-fit terminal according to the present invention, when a depth analysis by XPS (X-ray photoelectron spectroscopy) is carried out, a position (DI) where an atomic concentration (at%) of Sn or In of the A layer is a maximum value, a position (D2) where an atomic concentration (at%) of Ag, Au, Pt, Pd, Ru, Rh, Os, or Ir of the B layer is a maximum value, and a position (D3) where an atomic concentration (at%) of Ni, Cr, Mn, Fe, Co, or Cu of the C layer is a maximum value are present in the order of Di, D2, and D3 from the outermost surface.
[0027]
In further another embodiment of the press-fit terminal according to the present invention, when a depth analysis by XPS (X-ray photoelectron spectroscopy) is carried out, the A layer has a maximum value of an atomic concentration (at%) of Sn or In of 10 at% or higher, and the B layer has a maximum value of an atomic concentration (at%) of Ag, Au, Pt, Pd, Ru, Rh, Os, or Ir of 10 at% or higher; and a depth where the C layer has an atomic concentration (at%) of Ni, Cr, Mn, Fe, Co, or Cu of 25% or higher is 50 nm or more.
[0028]
In further another embodiment of the press-fit terminal according to the present invention, the A layer has a thickness of 0.01 to 0.1 m.
[0029]

- 17 -In further another embodiment of the press-fit terminal according to the present invention, the A layer has a deposition amount of Sn, In of 7 to 75 g/cm2.
[0030]
In further another embodiment of the press-fit terminal according to the present invention, the B layer has a thickness of 0.005 to 0.1 gm.
[0031]
In further another embodiment of the press-fit terminal according to the present invention, the B layer has a deposition amount of Ag, Au, Pt, Pd, Ru, Rh, Os, Ir of 4 to 120 gg/cm2.
[0032]
In further another embodiment of the press-fit terminal according to the present invention, the C layer has a cross-section Vickers hardness of Hv300 or higher.
[0033]
In further another embodiment of the press-fit terminal according to the present invention, the cross-section Vickers hardness and the thickness of the C layer satisfy the following expression:
Vickers hardness (Hv) -376.22Ln (thickness: gm) +
86.411.
[0034]
In further another embodiment of the press-fit terminal according to the present invention, the underlayer (C layer) has a cross-section indentation

- 18 -hardness of 2,500 MPa or higher, the indentation hardness being a hardness acquired by measuring an impression made on the cross-section of the underlayer (C layer) by a load of 0.1 mN in an ultrafine hardness test.
[0035]
In further another embodiment of the press-fit terminal according to the present invention, the cross-section indentation hardness, which is a hardness acquired by measuring an impression made on the cross-section of the underlayer (C layer) by a load of 0.1 mN
in an ultrafine hardness test, and the thickness of the underlayer (C layer) satisfy the following expression:
Indentation hardness (MPa) ?_ -3998.4Ln (thickness:
pm) + 1178.9.
[0036]
In further another embodiment of the press-fit terminal according to the present invention, the C layer has a cross-section Vickers hardness of Hv1,000 or lower.
[0037]
In further another embodiment of the press-fit terminal according to the present invention, the underlayer (C layer) has a cross-section indentation hardness of 10,000 MPa or lower, the indentation hardness being a hardness acquired by measuring an impression made on the cross-section of the underlayer (C layer) by a load of 0.1 mN in an ultrafine hardness test.
[0038]

- 19 -In further another embodiment of the press-fit terminal according to the present invention, when a depth analysis by XPS (X-ray photoelectron spectroscopy) is carried out, between a position (DI) where an atomic concentration (at%) of Sn or In of the A layer is a maximum value and a position (Dfl where an atomic concentration (at%) of Ni, Cr, Mn, Fe, Co, Cu, or Zn of the C layer is a maximum value, a region having 40 at% or more of Ag, Au, Pt, Pd, Ru, Rh, Os, or Ir is present in a thickness of 1 nm or larger.
[0039]
In further another embodiment of the press-fit terminal according to the present invention, when an elemental analysis of a surface of the A layer is carried out by a survey measurement by XPS (X-ray photoelectron spectroscopy), a content of Sn, In is 2 at% or higher.
[0040]
In further another embodiment of the press-fit terminal according to the present invention, when an elemental analysis of a surface of the A layer is carried out by a survey measurement by XPS (X-ray photoelectron spectroscopy), a content of Ag, Au, Pt, Pd, Ru, Rh, Os, or Ir is lower than 7 at%.
[0041]
In further another embodiment of the press-fit terminal according to the present invention, when an elemental analysis of a surface of the A layer is carried ak 02863505 2014-10-15

- 20 -out by a survey measurement by XPS (X-ray photoelectron spectroscopy), a content of 0 is lower than 50 at%.
[0042]
In further another embodiment of the press-fit terminal according to the present invention, the press-fit terminal is fabricated by forming surface-treated layers on the substrate connection part in the order of the C layer, the B layer, and the A layer by a surface treatment, and thereafter heat-treating the surface-treated layers at a temperature of 50 to 500 C within 12 hours.
[0043]
Further another aspect of the present invention is an electronic component comprising the press-fit terminal according to the present invention.
In a further embodiment of the present invention, there is provided a press-fit terminal comprising:
a female terminal connection part provided at one side of an attached part to be attached to a housing;
and a substrate connection part provided at the other side and attached to a substrate by press-fitting the substrate connection part into a through-hole formed in the substrate, wherein at least the substrate connection part has a surface structure comprising:
an A layer formed as an outermost surface layer and formed of Sn, In, or an alloy thereof;

- 20a -a B layer formed below the A layer and comprising Ag, Au, Pt, Pd, Ru, Rh, Os, Ir or any combination thereof; and a C layer formed below the B layer and comprising Ni, Cr, Mn, Fe, Co, Cu or any combination thereof, wherein the A layer has a thickness of 0.002 to 0.2 pm, wherein the B layer has a thickness of 0.001 to 0.3 pm, and wherein the C layer has a thickness of 0.05 pm or larger.
In a further embodiment of the present invention, there is provided a press-fit terminal comprising:
a female terminal connection part provided at one side of an attached part to be attached to a housing;
and a substrate connection part provided at the other side and attached to a substrate by press-fitting the substrate connection part into a through-hole formed in the substrate, wherein at least the substrate connection part has a surface structure comprising:
an A layer formed as an outermost surface layer and formed of Sn, In, or an alloy thereof;
a B layer formed below the A layer and comprising: Ag, Au, Pt, Pd, Ru, Rh, Os, Ir or any combination thereof; and a C layer formed below the B layer and comprising Ni, Cr, Mn, Fe, Co, Cu or any combination thereof, wherein the A layer has a deposition amount of Sn, In of 1 to 150 pg/cm2, - 20b -wherein the B layer has a deposition amount of Ag, Au, Pt, Pd, Ru, Rh, Os, Ir of 1 to 330 pg/cm2, and wherein the C layer has a deposition amount of Ni, Cr, Mn, Fe, Co, Cu of 0.03 mg/cm2 or larger.
[0044]
Some embodiments of the present invention may provide a press-fit terminal which may have excellent whisker resistance and may have a low inserting force, may be unlikely to cause shaving of plating when the press-fit terminal is inserted into a substrate, and may have a high heat resistance, and an electronic component using the same.
[Brief Description of Drawings]
[0045]
,

- 21 -[Figure 1] Figure 1 is an illustrative diagram of a press-fit terminal according to an embodiment of the present invention.
[Figure 2] Figure 2 is an illustrative diagram showing a constitution of a metal material used for the press-fit terminal according to the embodiment of the present invention.
[Figure 3] Figure 3 is a depth measurement result by XPS
(X-ray photoelectron spectroscopy) according to Example 3.
[Figure 4] Figure 4 is a survey measurement result by XPS
(X-ray photoelectron spectroscopy) according to Example 3.
[Description of Embodiments]
[0046]
Hereinafter, a press-fit terminal according to an embodiment of the present invention will be described.
Figure 1 is an illustrative diagram of a press-fit terminal according to the embodiment. As shown in Figure 2, in a metal material 10 used as a material of the press-fit terminal, a C layer 12 is formed on the surface of a base material 11; a B layer 13 is formed on the surface of the C layer 12; and an A layer 14 is formed on the surface of the B layer 13.
[0047]
<Constitution of press-fit terminal>
(Base material)

- 22 -The base material 11 is not especially limited, but usable are metal base materials, for example, copper and copper alloys, Fe-based materials, stainless steels, titanium and titanium alloys, and aluminum and aluminum alloys. The structure and shape or the like of the press-fit terminal are not especially limited. A general press-fit terminal includes a plurality of terminals (multi-pin) arranged in parallel, and is fixed to a substrate.
[0048]
(A layer) The A layer needs to be Sn, In, or an alloy thereof.
Sn and In, though being oxidative metals, have a feature of being relatively soft among metals. Therefore, even if an oxide film is formed on the Sn and In surface, when the press-fit terminal is inserted into the substrate, since the oxide film is easily shaven to thereby make the contact of metals, a low contact resistance can be provided.
Sn and In are excellent in the gas corrosion resistance to gases such as chlorine gas, sulfurous acid gas, and hydrogen sulfide gas; and for example, in the case where Ag, inferior in the gas corrosion resistance, is used for the B layer 13; Ni, inferior in the gas corrosion resistance, is used for the C layer 12; and copper and a copper alloy, inferior in the gas corrosion resistance, are used for the base material 11, Sn and In

- 23 -have a function of improving the gas corrosion resistance of the press-fit terminal. Here, among Sn and In, Sn is preferable because In is under a strict regulation based on the technical guideline regarding the health hazard prevention of the Ministry of Health, Labor, and Welfare.
[0049]
The composition of the A layer 14 comprises 50 mass%
or more of Sn, In, or the total of Sn and In, and the other alloy component(s) may be constituted of one or two or more metals selected from the group consisting of Ag, As, Au, Bi, Cd, Co, Cr, Cu, Fe, In, Mn, Mo, Ni, Pb, Sb, Sn, W, and Zn. The composition of the A layer 14 forms an alloy (for example, the A layer is subjected to Sn-Ag plating), and thereby, the composition further improves a whisker resistance, provides a further low inserting force, is further unlikely to cause shaving of plating when the press-fit terminal is inserted into the substrate, and improves a heat resistance in some cases.
[0050]
The thickness of the A layer 14 needs to be 0.002 to 0.2 m. The thickness of the A layer 14 is preferably 0.01 to 0.1 m. With the thickness of the A layer 14 of smaller than 0.002 m, a sufficient gas corrosion resistance cannot be provided; and when the press-fit terminal is subjected to a gas corrosion test using chlorine gas, sulfurous acid gas, hydrogen sulfide gas, or the like, the press-fit terminal is corroded to

- 24 -thereby largely increase the contact resistance as compared with before the gas corrosion test. In order to provide a more sufficient gas corrosion resistance, the thickness is preferably 0.01 pm or larger. If the thickness becomes large, the adhesive wear of Sn and In becomes much; the inserting force becomes high; and the plating is liable to be shaven when the press-fit terminal is inserted into the substrate. In order to provide a more sufficiently low inserting force and be further unlikely to cause shaving of plating when the press-fit terminal is inserted into the substrate, the thickness is made to be 0.2 pm or smaller. The thickness is more preferably 0.15 pm or smaller, and still more preferably 0.10 pm or smaller.
[0051]
The deposition amount of Sn, In of the A layer 14 needs to be 1 to 150 pg/cm2. The deposition amount of the A layer 14 is preferably 7 to 75 pg/cm2. Here, the reason to define the deposition amount will be described.
For example, in some cases of measuring the thickness of the A layer 14 by an X-ray fluorescent film thickness meter, due to an alloy layer formed between the A layer and the underneath B layer, an error may be produced in the value of the measured thickness. By contrast, the case of the control using the deposition amount can carry out more exact quality control, not influenced by the formation situation of the alloy layer. If the

- 25 -deposition amount of Sn, In of the A layer 14 is smaller than 1 pg/cm2, a sufficient gas corrosion resistance cannot be provided. If the press-fit terminal is subjected to a gas corrosion test using chlorine gas, sulfurous acid gas, hydrogen sulfide gas, or the like, the press-fit terminal is corroded to thereby largely increase the contact resistance as compared with before the gas corrosion test. In order to provide a more sufficient gas corrosion resistance, the deposition amount is preferably 7 pg/cm2 or larger. If the deposition amount becomes large, the adhesive wear of Sn and In becomes much; the inserting force becomes high;
and the plating is liable to be shaven when the press-fit terminal is inserted into the substrate. In order to provide a more sufficiently low inserting force and be further unlikely to cause shaving of plating when the press-fit terminal is inserted into the substrate, the deposition amount is made to be 150 pg/cm2 or smaller.
The deposition amount is more preferably 110 pg/cm2 or smaller, and still more preferably 75 pg/cm2 or smaller.
[0052]
(B layer) The B layer 13 needs to be constituted of one or two or more selected from the group consisting of Ag, Au, Pt, Pd, Ru, Rh, Os, and Ir. Ag, Au, Pt, Pd, Ru, Rh, Os, and Ir have a feature of relatively having a heat resistance among metals. Therefore, the B layer suppresses the

- 26 -diffusion of the compositions of the base material 11 and the C layer 12 to the A layer 14 side, and improves the heat resistance. These metals form compounds with Sn and In of the A layer 14 and suppress the oxide film formation of Sn and In. Among Ag, Au, Pt, Pd, Ru, Rh, Os, and Ir, Ag is more desirable from the viewpoint of the conductivity. Ag has high conductivity. For example, in the case of using Ag for applications of high-frequency signals, the skin effect reduces the impedance resistance.
The alloy composition of the B layer 13 comprises 50 mass% or more of Ag, Au, Pt, Pd, Ru, Rh, Os, Ir, or the total of Ag, Au, Pt, Pd, Ru, Rh, Os, and Ir, and the other alloy component(s) may be constituted of one or two or more metals selected from the group consisting of Ag, Au, Bi, Cd, Co, Cu, Fe, In, Ir, Mn, Mo, Ni, Pb, Pd, Pt, Rh, Ru, Sb, Se, Sn, W, Tl, and Zn. The composition of the B layer 13 forms an alloy (for example, the B layer is subjected to Ag-Sn plating), and thereby, the composition further improves a whisker resistance, provides a further low inserting force, is further unlikely to cause shaving of plating when the press-fit terminal is inserted into the substrate, and improves a heat resistance in some cases.
[0053]
The thickness of the B layer 13 needs to be 0.001 to 0.3 m. The thickness of the B layer 13 is preferably 0.005 to 0.1 m. If the thickness is smaller than 0.001

- 27 -gm, the base material 11 or the C layer 12 and the A
layer form an alloy, and the contact resistance after a heat resistance test becomes worsened. In order to provide a more sufficient heat resistance, the thickness is preferably 0.005 gm or larger. If the thickness becomes large, the inserting force becomes high; and the plating is liable to be shaven when the press-fit terminal is inserted into the substrate. In order to provide a more sufficiently low inserting force and be further unlikely to cause shaving of plating when the press-fit terminal is inserted into the substrate, the thickness is 0.3 gm or smaller, more preferably 0.15 gm or smaller, and more preferably 0.10 gm or smaller.
[0054]
The deposition amount of Ag, Au, Pt, Pd, Ru, Rh, Os, Ir, or an alloy thereof of the B layer 13 needs to be 1 to 330 gg/cm2. The deposition amount of the B layer 13 is preferably 4 to 120 gg/cm2. Here, the reason to define the deposition amount will be described. For example, in some cases of measuring the thickness of the B layer 13 by an X-ray fluorescent film thickness meter, due to an alloy layer formed between the A layer 14 and the underneath B layer 13, an error may be produced in the value of the measured thickness. By contrast, the case of the control using the deposition amount can carry out more exact quality control, not influenced by the formation situation of the alloy layer. With the

- 28 -deposition amount of smaller than 1 g/cm2, the base material 11 or the C layer 12 and the A layer form an alloy, and the contact resistance after a heat resistance test becomes worsened. In order to provide a more sufficient heat resistance, the deposition amount is preferably 4 pg/cm2 or larger. If the deposition amount is large, the inserting force becomes high; and the plating is liable to be shaven when the press-fit terminal is inserted into the substrate. In order to provide a more sufficiently low inserting force and be further unlikely to cause shaving of plating when the press-fit terminal is inserted into the substrate, the deposition amount is 330 g/cm2 or smaller, more preferably 180 g/cm2 or smaller, and still more preferably 120 g/cm2 or smaller.
[0055]
(C layer) Between the base material 11 and the B layer 13, the C layer 12 constituted of one or two or more selected from the group consisting of Ni, Cr, Mn, Fe, Co, and Cu needs to be formed. By forming the C layer 12 by using one or two or more metals selected from the group consisting of Ni, Cr, Mn, Fe, Co, and Cu, the thin film lubrication effect is improved due to the formation of the hard C layer, and thereby a sufficiently low inserting force can be provided. The C layer 12 prevents the diffusion of constituting metals of the base material

- 29 -11 to the B layer to thereby improve the durability including the suppression of the increase in the contact resistance after the heat resistance test and the gas corrosion resistance test.
[0056]
The alloy composition of the C layer 12 comprises 50 mass% or more of the total of Ni, Cr, Mn, Fe, Co, and Cu, and may further comprise one or two or more selected from the group consisting of B, P, Sn, and Zn. By making the alloy composition of the C layer 12 to have such a constitution, the C layer is further hardened to thereby further improve the thin film lubrication effect to provide the low inserting force; and the alloying of the C layer 12 further prevents the diffusion of constituting metals of the base material 11 to the B layer to thereby improve the durability including the suppression of the increase in the contact resistance after the heat resistance test and the gas corrosion resistance test.
[0057]
The thickness of the C layer 12 needs to be 0.05 m or larger. With the thickness of the C layer 12 of smaller than 0.05 m, the thin film lubrication effect by the hard C layer decreases to thereby provide the high inserting force; and the constituting metals of the base material 11 become liable to diffuse to the B layer to thereby worsen the durability including the increase in

- 30 -the contact resistance after the heat resistance test and the gas corrosion resistance test.
[0058]
The deposition amount of Ni, Cr, Mn, Fe, Co, Cu of the C layer 12 needs to be 0.03 mg/cm2 or larger. Here, the reason to define the deposition amount will be described. For example, in some cases of measuring the thickness of the C layer 12 by an X-ray fluorescent film thickness meter, due to alloy layers formed with the A
layer 14, the B layer 13, the base material 11, or the like, an error may be produced in the value of the measured thickness. By contrast, the case of the control using the deposition amount can carry out more exact quality control, not influenced by the formation situation of the alloy layer. With the deposition amount of smaller than 0.03 mg/cm2, the thin film lubrication effect by the hard C layer decreases to thereby provide the high inserting force; and the constituting metals of the base material 11 become liable to diffuse to the B
layer to thereby worsen the durability including the increase in the contact resistance after the heat resistance test and the gas corrosion resistance test.
[0059]
(Heat treatment) After the A layer 14 is formed, for the purpose of further improving a whisker resistance, providing a further low inserting force, being further unlikely to

- 31 -cause shaving of plating when the press-fit terminal is inserted into the substrate, or improving a heat resistance, a heat treatment may be carried out. The heat treatment makes it easy for the A layer 14 and the B
layer 13 to form an alloy layer to thereby improve the whisker resistance, to be thereby further unlikely to cause shaving of plating when the press-fit terminal is inserted into the substrate, to thereby improve the heat resistance, and to thereby provide further low adhesion of Sn to provide a low inserting force. Here, the heat treatment is not limited. However, the heat treatment is preferably carried out at a temperature of 50 to 500 C
within 12 hours. If the temperature is lower than 50 C, the A layer 14 and the B layer 13 hardly form the alloy layer because of the low temperature. If the temperature is higher than 500 C, the base material 11 or the C layer 12 diffuses to the B layer 13 and the A layer 14 to thereby provide the high contact resistance in some cases.
If the heat treatment time is longer than 12 hours, the base material 11 or the C layer 12 diffuses to the B
layer 13 and the A layer 14 to thereby provide the high contact resistance in some cases.
[0060]
(Post-treatment) On the A layer 14 or after the heat treatment is carried out on the A layer 14, for the purpose of providing a further low inserting force, being further

- 32 -unlikely to cause shaving of plating when the press-fit terminal is inserted into the substrate, and improving a heat resistance, a post-treatment may be carried out.
The post-treatment improves the lubricity, to thereby provide a further low inserting force, makes shaving of plating unlikely to be caused, and suppresses the oxidation of the A layer and the B layer, to thereby improve the durability such as a heat resistance and a gas corrosion resistance. The post-treatment specifically includes a phosphate salt treatment, a lubrication treatment, and a silane coupling treatment, using inhibitors. Here, the post-treatment is not limited.
[0061]
<Properties of metal material>
The Vickers hardness as measured from the surface of the A layer 14 is preferably Hv100 or higher. With the Vickers hardness as measured from the surface of the A
layer 14 of Hv100 or higher, the hard A layer improves the thin film lubrication effect and provides the low inserting force. By contrast, the Vickers hardness as measured from the surface of the A layer 14 is preferably Hv1,000 or lower. With the Vickers hardness as measured from the surface of the A layer 14 of Hv1,000 or lower, the bending workability is improved; and in the case where the press-fit terminal according to the present invention is press-formed, cracks are hardly generated in

- 33 -the formed portion, and the decrease in the gas corrosion resistance is suppressed.
The indentation hardness as measured from the surface of the A layer 14 is preferably 1,000 MPa or higher. Here, the indentation hardness as measured from the surface of the A layer 14 is a hardness acquired by measuring an impression made on the surface of the A
layer by a load of 0.1 mN in an ultrafine hardness test.
With the surface indentation hardness of the A layer 14 of 1,000 MPa or higher, the hard A layer improves the thin film lubrication effect and provides a low inserting force. By contrast, the Vickers indentation hardness as measured from the surface of the A layer 14 is preferably 10,000 MPa or lower. With the surface indentation hardness of the A layer 14 of 10,000 MPa or lower, the bending workability is improved; and in the case where the press-fit terminal according to the present invention is press-formed, cracks are hardly generated in the formed portion, and the decrease in the gas corrosion resistance is suppressed.
[0062]
The arithmetic average height (Ra) of the surface of the A layer 14 is preferably 0.1 gm or lower. With the arithmetic average height (Ra) of the surface of the A
layer 14 of 0.1 gm or lower, since convex portions, which are relatively easily corroded, become few and the

- 34 -surface becomes smooth, the gas corrosion resistance is improved.
The maximum height (Rz) of the surface of the A
layer 14 is preferably 1 gm or lower. With the maximum height (Rz) of the surface of the A layer 14 of 1 pla or lower, since convex portions, which are relatively easily corroded, become few and the surface becomes smooth, the gas corrosion resistance is improved.
The surface reflection density of the A layer 14 is preferably 0.3 or higher. With the surface reflection density of the A layer 14 of 0.3 or higher, since convex portions, which are relatively easily corroded, become few and the surface becomes smooth, the gas corrosion resistance is improved.
[0063]
The cross-section Vickers hardness of the C layer 12 is preferably Hv300 or higher. With the cross-section Vickers hardness of the C layer 12 of Hv300 or higher, the C layer is further hardened to thereby further improve the thin film lubrication effect to provide a low inserting force. By contrast, the cross-section Vickers hardness of the C layer 12 is preferably Hv1,000 or lower.
With the cross-section Vickers hardness of the C layer 12 of Hv1,000 or lower, the bending workability is improved;
and in the case where the press-fit terminal according to the present invention is press-formed, cracks are hardly

- 35 -generated in the formed portion, and the decrease in the gas corrosion resistance is suppressed.
[0064]
The cross-section Vickers hardness of the C layer 12 and the thickness of the C layer 12 preferably satisfy the following expression:
Vickers hardness (Hv) -376.22Ln (thickness: pm) +
86.411.
If the cross-section Vickers hardness of the C layer 12 and the thickness of the C layer 12 satisfy the above expression, the C layer is further hardened to thereby further improve the thin film lubrication effect to provide the low inserting force.
Here, in the present invention, "Ln (thickness: pm)"
refers to a numerical value of a natural logarithm of a thickness (pm).
[0065]
The cross-section indentation hardness of the C
layer 12 is preferably 2,500 MPa or higher. Here, the cross-section indentation hardness of the C layer 12 is a hardness acquired by measuring an impression made on the cross-section of the C layer 12 by a load of 0.1 mN in an ultrafine hardness test. With the cross-section indentation hardness of the C layer 12 of 2,500 MPa or higher, the C layer is further hardened to thereby further improve the thin film lubrication effect to provide the low inserting force. By contrast, the cross-

- 36 -section indentation hardness of the C layer 12 is preferably 10,000 MPa or lower. With the cross-section indentation hardness of the C layer 12 of 10,000 MPa or lower, the bending workability is improved; and in the case where the press-fit terminal according to the present invention is press-formed, cracks are hardly generated in the formed portion, and the decrease in the gas corrosion resistance is suppressed.
[0066]
The cross-section indentation hardness of the C
layer 12 and the thickness of the C layer 12 preferably satisfy the following expression:
Indentation hardness (MPa) -3998.4Ln (thickness:
m) + 1178.9.
If the cross-section indentation hardness of the C layer 12 and the thickness of the C layer 12 satisfy the above expression, the C layer is further hardened to thereby further improve the thin film lubrication effect to provide the low inserting force.
[0067]
When a depth analysis by XPS (X-ray photoelectron spectroscopy) is carried out, it is preferable that a position (Di) where the atomic concentration (at%) of Sn or In of the A layer 14 is a maximum value, a position (D2) where the atomic concentration (at%) of Ag, Au, Pt, Pd, Ru, Rh, Os, or Ir of the B layer 13 is a maximum value, and a position (Dfl where the atomic concentration

- 37 -(at%) of Ni, Cr, Mn, Fe, Co, or Cu of the C layer 12 is a maximum value are present in the order of Di, D2, and D3 from the outermost surface. If the positions are not present in the order of Di, D2, and D3 from the outermost surface, there arises a risk that: a sufficient gas corrosion resistance cannot be provided; and when the press-fit terminal is subjected to a gas corrosion test using chlorine gas, sulfurous acid gas, hydrogen sulfide gas, or the like, the press-fit terminal is corroded to thereby largely increase the contact resistance as compared with before the gas corrosion test.
When a depth analysis by XPS (X-ray photoelectron spectroscopy) is carried out, it is preferable that: the A layer 14 has a maximum value of an atomic concentration (at%) of Sn or In of 10 at% or higher, and the B layer 13 has a maximum value of an atomic concentration (at%) of Ag, Au, Pt, Pd, Ru, Rh, Os, or Ir of 10 at% or higher;
and a depth where the atomic concentration (at%) of Ni, Cr, Mn, Fe, Co, or Cu of the C layer 12 is 25 at% or higher is 50 nm or more. In the case where the maximum value of the atomic concentration (at%) of Sn or In of the A layer 14, and the maximum value of the atomic concentration (at%) of Ag, Au, Pt, Pd, Ru, Rh, Os, or Ir of the B layer 13 are each lower than 10 at%; and where a depth where the atomic concentration (at%) of Ni, Cr, Mn, Fe, Co, or Cu of the C layer 12 is 25 at% or higher is shallower than 50 nm, there arises a risk that the

- 38 -inserting force is high, and the base material components diffuse to the A layer 14 or the B layer 13 to thereby worsen the heat resistance and the gas corrosion resistance.
When a depth analysis by XPS (X-ray photoelectron spectroscopy) is carried out, it is preferable that between a position ( i) where the atomic concentration (at%) of Sn or In of the A layer 14 is a maximum value and a position (Dfl where the atomic concentration (at%) of Ni, Cr, Mn, Fe, Co, Cu, or Zn of the C layer 12 is a maximum value, a region having 40 at% or more of Ag, Au, Pt, Pd, Ru, Rh, Os, or Ir is present in a thickness of 1 nm or larger. If the region is present in a thickness of smaller than 1 nm, for example, in the case of Ag, there arises a risk of worsening the heat resistance.
When an elemental analysis of the surface of the A
layer is carried out by a survey measurement by XPS (X-ray photoelectron spectroscopy), it is preferable that the content of Sn, In is 2 at% or higher. If the content of Sn, In is lower than 2 at%, for example, in the case of Ag, there arises a risk that the sulfurization resistance is inferior and the contact resistance largely increases. For example, in the case of Pd, there arises a risk that Pd is oxidized to thereby raise the contact resistance.
When an elemental analysis of the surface of the A
layer is carried out by a survey measurement by XPS (X-

- 39 -ray photoelectron spectroscopy), it is preferable that the content of Ag, Au, Pt, Pd, Ru, Rh, Os, or Ir is lower than 7 at%. If the content of Ag, Au, Pt, Pd, Ru, Rh, Os, or Ir is 7 at% or higher, for example, in the case of Ag, there arises a risk that the sulfurization resistance is inferior and the contact resistance largely increases.
For example, in the case of Pd, there arises a risk that Pd is oxidized to thereby raise the contact resistance.
When an elemental analysis of the surface of the A
layer is carried out by a survey measurement by XPS (X-ray photoelectron spectroscopy), it is preferable that the content of 0 is lower than 50 at%. If the content of 0 is 50 at% or higher, there arises a risk of raising the contact resistance.
[0068]
<Method for manufacturing a press-fit terminal>
A method for manufacturing the press-fit terminal according to the present invention is not limited. The press-fit terminal can be manufactured by subjecting a base material previously formed into a press-fit terminal shape by press-forming or the like to wet (electro-, electroless) plating, dry (sputtering, ion plating, or the like) plating, or the like.
[Examples]
[0069]
Hereinafter, although Examples of the present invention will be described with Comparative Examples,

- 40 -these are provided to better understand the present invention, and are not intended to limit the present invention.
[0070]
As Examples and Comparative Examples, samples to be formed by providing a base material, a C layer, a B layer, and an A layer in this order, and possibly heat-treating the resultant, were each fabricated under the conditions shown in the following Tables 1 to 7.
Specifications of press-fit terminals and through-holes are shown in Table 1; the fabrication condition of C layers is shown in Table 2; the fabrication condition of B layers is shown in Table 3; the fabrication condition of A layers is shown in Table 4; and the heat treatment condition is shown in Table 5. The fabrication conditions and the heat treatment conditions of the each layer used in each Example are shown in Table 6; and the fabrication conditions and the heat treatment conditions of the each layer used in each Comparative Example are shown in Table 7.
[0071]
[Table 1]
Specification of Press-Fit Specification of Through-Hole Terminal made by Tokiwa & Co., Inc., Thickness of substrate: 2 mm Press-fit terminal PCB through-hole: (I) 1 mm connector, R800 [0072]

- 41 -[Table 2]
Condition of Underlayers (C Layers) No. Surface Treatment Detail Method 1 Electroplating Plating liquid: Ni sulfamate plating liquid Plating temperature: 55 C
Current density: 0.5 to 4 A/dm2 2 Electroplating Plating liquid: Cu sulfate plating liquid Plating temperature: 30 C
Current density: 2.3 A/dm2 3 Electroplating Plating liquid: chromium sulfate liquid Plating temperature: 30 C
Current density: 4 A/dm2 4 Sputtering Target: having a predetermined composition Apparatus: sputtering apparatus made by Ulvac, Inc.
Output: DC 50 W
Argon pressure: 0.2 Pa Electroplating Plating liquid: Fe sulfate liquid Plating temperature: 30 C
Current density: 4 A/dm2 6 Electroplating Plating liquid: Co sulfate bath Plating temperature: 30 C
Current density: 4 A/dm2 7 Electroplating Plating liquid: Ni sulfamate plating liquid +
saccharin Plating temperature: 55 C
Current density: 4 A/dm2 8 Electroplating Plating liquid: Ni sulfamate plating liquid +
saccharin +
additive Plating temperature: 55 C
Current density: 4 A/dm2 [0073]

¨ 42 ¨
[Table 3]
Condition of Middle Layers (B Layers) No. Surface Treatment Detail Method 1 Electroplating Plating liquid: Ag cyanide plating liquid Plating temperature: 40 C
Current density: 0.2 to 4 AJdm2 2 Electroplating Plating liquid: Au cyanide plating liquid Plating temperature: 40 C
Current density: 0.2 to 4 A/dm2 3 Electroplating Plating liquid: chloroplatinic acid plating liquid Plating temperature: 40 C
Current density: 0.2 to 4 A/dm2 4 Electroplating Plating liquid: diammine palladium (II) chloride plating liquid Plating temperature: 40 C
Current density: 0.2 to 4 A/dm2 Electroplating Plating liquid: Ru sulfate plating liquid Plating temperature: 40 C
Current density: 0.2 to 4 A/dm2 6 Sputtering Target: having a predetermined composition Apparatus: sputtering apparatus made by Ulvac, Inc.
Output: DC 50 W
Argon pressure: 0.2 Pa 7 Electroplating Plating liquid: Sn methanesulfonate plating liquid Plating temperature: 40 C
Current density: 0.2 to 4 AJdm2 8 Electroplating Plating liquid: Cu sulfate plating liquid Plating temperature: 30 C
Current density: 2.3 A/dm2 [0074]

[Table 4]
Condition of Base Material of Outermost Surface Layers (A Layers) No. Surface Treatment Detail Method 1 Electroplating Plating liquid: Sn methanesulfonate plating liquid Plating temperature: 40 C
Current density: 0.2 to 4 A/dm2 2 Sputtering Target: having a predetermined composition Apparatus: sputtering apparatus made by Ulvac, Inc.
Output: DC 50 W
Argon pressure: 0.2 Pa 3 Electroplating Plating liquid: Ag cyanide plating liquid Plating temperature: 40 C
Current density: 0.2 to 4 A/dm2 [0075]
[Table 5]
Heat Treatment Condition No. Temperature [ C] Time [second]

3 30 12 hours 4 50 12 hours 50 20 hours [0076]

[Table 6-1]
Example No. Outermost Surface Middle Layer Underlayer (C Heat Layer (A Layer) (B Layer) Layer) Treatment Condition No. Condition No. Condition No. Condition No.
see Table 4 see Table 3 see Table 2 see Table 5 [0077]

¨ 45 ¨
[Table 6-2]
Example No. Outermost Surface Middle Layer Underlayer (C Heat Treatment Layer (A Layer) (B Layer) Layer) Condition No.
Condition No. Condition No. Condition No. see Table 5 see Table 4 see Table 3 see Table 2

42 1 6 1 - - -

43 1 6 1 - - -

44 1 6 1 - - -

45 1 6 1 - - -

46 1 6 1 - - -

47 1 6 1 - - -

48 1 6 1 - - -

49 1 6 1 - - -

50 1 6 1 - - -

51 1 6 1 - - -

52 1 6 1 - - -

53 1 1 3 - - -

54 1 1 4 - - -

55 1 1 5 - - -

56 1 1 6 - - -

57 1 1 2 - - -

58 1 1 4 - - -

59 1 1 4 - - -

60 1 1 4 - - -

61 1 1 4 - - -

62 1 1 4 - - -

63 1 1 4 - - -

64 1 1 4 - - -

65 1 1 4 - - -

66 1 1 4 - - -

67 1 1 1 - - -

68 1 1 7 - - -

69 1 1 8 - - -

70 1 1 1 - - -[0078]

¨ 46 ¨
[Table 6-3]
Example No. Outermost Surface Middle Layer Underlayer (C Heat Layer (A Layer) (B Layer) Layer) Treatment Condition No. Condition No. Condition No. Condition No.
see Table 4 see Table 3 see Table 2 see Table 5

71 1 1 1 ---

72 1 1 1 ---

73 1 1 1 ---

74 1 1 1 ---

75 1 1 1 ---

76 1 1 1 ---

77 1 1 1 ---

78 1 1 1 ---

79 1 1 1 ---

80 1 1 1 ---

81 1 1 7 ---

82 1 1 8 ---

83 1 1 7 ---

84 1 1 7 ---

85 1 1 8 ---

86 1 1 8 ---

87 1 1 4 ---

88 1 1 4 ---

89 1 1 1 1

90 1 1 1 2

91 1 2 1 ---

92 1 2 1 ---

93

94 2 1 1 ---

95 1 1 1 ---

96 1 1 1 3

97 1 1 1 4

98 1 1 1 5

99 1 1 1 6

100 1 1 1 7

101 1 1 1 8 [ 0 0 7 9 ]

[Table 7]
Comparative Outermost Surface Middle Layer Underlayer (C Heat Treatment Example No. Layer (A Layer) (B Layer) Layer) Condition No.
Condition No. Condition No. Condition No. see Table 5 see Table 4 see Table 3 see Table 2 1 1 ___ 1 1 [0080]
(Measurement of a thickness) The thicknesses of an A layer, a B layer, and a C
layer were measured by carrying out the each surface treatment on a base material, and measuring respective actual thicknesses by an X-ray fluorescent film thickness meter (made by Seiko Instruments Inc., SEA5100, collimator: 0.1 mrnd) ) .
[0081]
(Measurement of a deposition amount) Each sample was acidolyzed with sulfuric acid, nitric acid, or the like, and measured for a deposition amount of each metal by ICP (inductively coupled plasma) atomic emission spectroscopy. The acid to be specifically used depends on the composition of the each sample.
[0082]
(Determination of a composition) The composition of each metal was calculated based on the measured deposition amount.
[0083]
(Determination of a layer structure) The layer structure of the obtained sample was determined by a depth profile by XPS (X-ray photoelectron spectroscopy) analysis. The analyzed elements are compositions of an A layer, a B layer, and a C layer, and C and O. These elements are made as designated elements.
With the total of the designated elements being taken to be 100%, the concentration (at%) of the each element was analyzed. The thickness by the XPS (X-ray photoelectron spectroscopy) analysis corresponds to a distance (in terms of Si02) on the abscissa of the chart by the analysis.
The surface of the obtained sample was also subjected to a qualitative analysis by a survey measurement by XPS (X-ray photoelectron spectroscopy) analysis. The resolution of the concentration by the qualitative analysis was set at 0.1 at%.
An XPS apparatus to be used was 5600MC, made by Ulvac-Phi, Inc., and the measurement was carried out under the conditions of ultimate vacuum: 5.7 x 10-9 Torr, exciting source: monochromated AlKa, output: 210 W, detection area: 800 m(1), incident angle: 45 , takeoff angle: 45 , and no neutralizing gun, and under the following sputtering condition.
Ion species: Ar+
Acceleration voltage: 3 kV
Sweep region: 3 mm x 3 mm Rate: 2.8 nm/min (in terms of Si02) [0084]
(Evaluations) Each sample was evaluated for the following items.
A. Inserting force The inserting force was evaluated by measuring an inserting force when a press-fit terminal was inserted into a substrate. A measurement apparatus used in the test was 1311NR, made by Aikoh Engineering Co., Ltd. The press-fit terminal was slid for the test in a state where the substrate was fixed. The number of the samples was set to be five; and a value obtained by averaging the values of the maximum inserting forces of the samples was employed as the inserting force. Samples of Comparative Example 1 were employed as a blank material for the inserting force.
The target of the inserting force was lower than 85%
of the maximum inserting force of Comparative Example 1.
Because Comparative Example 4 having an inserting force of 90% of the maximum inserting force of Comparative Example 1 was present as an actual product, the inserting force lower than 85% of the maximum inserting force of Comparative Example 1 and lower than that in Comparative Example 4 by 5% or more was targeted.
[0085]
B. Whisker The press-fit terminal was inserted into the through-hole of the substrate by a hand press, and a thermal shock cycle test (JETTA ET-7410) was carried out.
The sample whose test had been finished was observed at a magnification of 100 to 10,000 times by a SEM (made by JEOL Ltd., type: JSM-5410) to observe the generation situation of whiskers.
Thermal shock cycle test>
Low temperature -40 C x 30 minutes 4-> high temperature 85 C x 30 minutes/cycle x 1000 cycles The target property was that no whiskers of 20 m or longer in length were generated, but the top target was that no whisker at all was generated.
[0086]
C. Contact resistance The contact resistance was measured using a contact simulator CRS-113-Au, made by Yamasaki-Seiki Co., Ltd., by a four-terminal method under the condition of a contact load of 50 g. The number of the samples was made to be five, and a range of from the minimum value to the maximum value of the samples was employed. The target property was a contact resistance of 10 mfl or lower. The contact resistance was classified into 1 to 3 mi-2, 3 to 5 mO, and higher than 5 mil.
[0087]
D. Heat resistance The heat resistance was evaluated by measuring the contact resistance of a sample after an atmospheric heating (175 C x 500 h) test. The target property was a contact resistance of 10 mf2 or lower, but the top target was made to be no variation (being equal) in the contact resistance before and after the heat resistance test.
The heat resistance was classified into 1 to 4 mD, 2 to 4 m.Q, 2 to 5 mQ, 3 to 6 m12, 3 to 7 mO, 6 to 9 mn, and higher than 10 mi) in terms of contact resistance.
[0088]
E. Gas corrosion resistance The gas corrosion resistance was evaluated by three test environments shown in (1) to (3) described below.
The evaluation of the gas corrosion resistance was carried out by using the contact resistance of a sample after the environment tests of (1) to (3). The target property was a contact resistance of 10 mC2 or lower, but the top target was made to be no variation (being equal) in the contact resistance before and after the gas corrosion resistance test. The gas corrosion resistance was classified into 1 to 3 mi-2, 1 to 4 mn, 2 to 4 mn, 2 to 6 an, 3 to 5 riLQ, 3 to 7 ni0, 4 to 7 IrD, 5 to 8 rrn, 6 to 9 n1.0, and higher than 10 mn in terms of contact resistance.
(1) Salt spray test Salt concentration: 5%
Temperature: 35 C
Spray pressure: 98 10 kPa Exposure time: 96 h (2) Sulfurous acid gas corrosion test Sulfurous acid concentration: 25 ppm Temperature: 40 C
Humidity: 80% RH
Exposure time: 96 h (3) Hydrogen sulfide gas corrosion test Sulfurous acid concentration: 10 ppm Temperature: 40 C
Humidity: 80% RH
Exposure time: 96 h [0089]
G. Bending workability The bending workability was evaluated by a 90 bending of a sample under the condition that the ratio of the thickness and the bending radius of the sample became 1 by using a letter-W-shape die. The evaluation was made as good in the case where no crack was observed in the observation of the surface of the bending-worked portion by an optical microscope, posing no practical problem;

and as poor in the case where any cracks were observed therein.
[0090]
H. Vickers hardness The Vickers hardnesses of an A layer and a C layer were measured by making an impression by a load of 980.7 mN (Hv0.1) from the surface of the A layer and the cross-section of the C layer in a load retention time of 15 sec.
[0091]
I. Indentation hardness The indentation hardnesses of an A layer and a C
layer were measured by making an impression on the surface of the A layer and the cross-section of the C
layer at a load of 0.1 mN by an ultrafine hardness tester (ENT-2100, made by Elionix Inc.).
[0092]
J. Surface roughness The surface roughnesses (arithmetic average height (Ra) and maximum height (Rz)) were measured according to JIS B 0601 by using a non-contact type three dimensional measurement instrument (made by Mitaka Kohki Co., Ltd., type: NH-3). The measurement was carried out five times per sample, with a cutoff of 0.25 mm and a measurement length of 1.50 mm.
[0093]
K. Reflection density The reflection density was measured using a densitometer (ND-1, made by Nippon Denshoku Industries Co., Ltd.).
[0094]
L. Generation of powder The press-fit terminal inserted into the through-hole was extracted from the through-hole, and the cross-section of the press-fit terminal was observed at a magnification of 100 to 10,000 times by a SEM (made by JEOL Ltd., type: JSM-5410) to observe the generation status of powder. The press-fit terminal with which the diameter of the powder was smaller than 5 m was made as good; the press-fit terminal with which the diameter of the powder was 5 to smaller than 10 m was made as average; and the press-fit terminal with which the diameter of the powder was 10 m or larger was made as poor.
The respective conditions and evaluation results are shown in Tables 8 to 22.
[0095]

[Table 8]
Heat A Layer B Layer C Layer Treatme nt Thickne Depositio Depositio Depositio ss ss ss Compositi n Compositi Thickne n Compositi Thickne n Conditio on Amount on Amount on Amount n ilmli blecm21 [I-tmi [I-Lecm2i [pm] [mg/cm2]
1 Sn 0.2 146 Ag 0.3 315 Ni 1.0 0.9 None 2 Sn 0.2 146 Ag 0.001 1 Ni 1.0 0.9 None 3 Sn 0.03 22 Ag 0.03 32 Ni 1.0 0.9 None 4 Sn 0.002 1 Ag 0.3 315 Ni 1.0 0.9 None Sn 0.002 1 Ag 0.001 1 Ni 1.0 0.9 None 6 In 0.03 22 Ag 0.03 32 Ni 1.0 0.9 None 7 Sn-2Ag 0.03 22 Ag 0.03 32 Ni 1.0 0.9 None 8 Sn-2As 0.03 22 Ag 0.03 32 Ni 1.0 0.9 None 9 Sn-2Au 0.03 22 Ag 0.03 32 Ni 1.0 0.9 None Sn-2Bi 0.03 22 Ag 0.03 32 Ni 1.0 0.9 None Sn-2Cd 0.03 22 Ag 0.03 32 Ni 1.0 0.9 None Sn-2Co 0.03 22 Ag 0.03 32 Ni 1.0 0.9 None Sn-2Cr 0.03 22 Ag 0.03 32 Ni 1.0 0.9 None Sn-2Cu 0.03 22 Ag 0.03 32 Ni 1.0 0.9 None Sn-2Fe 0.03 22 Ag 0.03 32 Ni 1.0 0.9 None Sn-2In 0.03 22 Ag 0.03 32 Ni 1.0 0.9 None Sn-2Mn 0.03 22 Ag 0.03 32 Ni 1.0 0.9 None a.) 7 CI. 1 Sn-2Mo i 0.03 22 Ag 0.03 32 =Ni 1.0 0.9 None 8 .

Sn-2Ni 0.03 22 Ag 0.03 32 Ni 1.0 0.9 None Sn-2Pb 0.03 22 Ag 0.03 32 Ni 1.0 0.9 None Sn-25b 0.03 22 Ag 0.03 32 Ni 1.0 0.9 None Sn-2W 0.03 22 Ag 0.03 32 Ni 1.0 0.9 None Sn-2Zn 0.03 22 Ag 0.03 32 Ni 1.0 0.9 None Sn 0.03 22 Au 0.03 32 Ni 1.0 0.9 None Sn 0.03 22 Pt 0.03 32 Ni 1.0 0.9 None Sn 0.03 22 Pd 0.03 32 Ni 1.0 0.9 None Sn 0.03 22 Ru 0.03 32 Ni 1.0 0.9 None Sn 0.03 22 Rh 0.03 32 Ni 1.0 0.9 None 8 .

Sn 0.03 22 Os 0.03 32 Ni 1.0 0.9 None Sn 0.03 22 Ir 0.03 32 Ni 1.0 0.9 None 3 Sn 0.03 22 Ag-2Au 0.03 32 Ni 1.0 0.9 None Sn 0.03 22 Ag-2Bi 0.03 32 Ni 1.0 0.9 None Sn 0.03 22 Ag-2Cd 0.03 32 Ni 1.0 0.9 None Sn 0.03 22 Ag-2Co 0.03 32 Ni 1.0 0.9 None Sn 0.03 22 Ag-2Cu 0.03 32 Ni 1.0 0.9 None Sn 0.03 22 Ag-2Fe 0.03 32 Ni 1.0 0.9 None Sn 0.03 22 Ag-21n 0.03 32 Ni 1.0 0.9 None Sn 0.03 22 Ag-21r 0.03 32 Ni 1.0 0.9 None Sn 0.03 22 Ag-2Mn 0.03 32 Ni 1.0 0.9 None Targe 0.002 15_ 0.0015_ 15_ 0.005_ 0.03 t 5_0.2 150 0.3 330 [0096]

[Table 9]
A Layer B Layer C Layer Heat Treatment z a o - a z c ..., a z a Condition =-' :-= S o L .2. g .2 E .9. C' -15 :g :- = =c-A ,7 0 6 0 g' a. 5 rA
0,.0 c-) E .7 .--p.. E 0 1-..) -.- u <
C E
:=
E- a) < O. ..=
C
C...) C...) C..) [gm] [Fte/CM2] himl [g/cm2] [pin] [mg/cm]
40 Sn 0.03 22 Ag-2Mo 0.03 32 Ni 1.0 0.9 None 41 Sn 0.03 22 Ag-2Ni 0.03 32 Ni 1.0 0.9 None 42 Sn 0.03 22 Ag-2Pb 0.03 32 Ni 1.0 0.9 None 43 Sn 0.03 22 Ag-2Pd 0.03 32 Ni 1.0 0.9 None 44 Sn 0.03 22 Ag-2Pt 0.03 32 Ni 1.0 0.9 None .i.g. 45 Sn 0.03 22 Ag-2Rh 0.03 32 Ni 1.0 0.9 None 46 Sn 0.03 22 Ag-2Ru 0.03 32 Ni 1.0 0.9 None 47 Sn 0.03 22 Ag-2Sb 0.03 32 Ni 1.0 0.9 None 48 Sn 0.03 22 Ag-2Se 0.03 32 Ni 1.0 0.9 None 49 Sn 0.03 22 Ag-2Sn 0.03 32 Ni 1.0 0.9 None 50 Sn 0.03 22 Ag-2W 0.03 32 Ni 1.0 0.9 None 51 Sn 0.03 22 Ag-2T1 0.03 32 Ni 1.0 0.9 None 52 Sn 0.03 22 Ag-2Zn 0.03 32 Ni 1.0 0.9 None 1 Sn 1.0 728 Ni 0.5 0.4 300 C x 5 sec.
2 Sn 0.6 437 Ni 0.5 0.4 300 C x 5 sec.
3 Sn 0.6 437 Ni 0.5 0.4 4 Sn 0.6 437 Cu 0.3 Ni 0.5 0.4 300 C x 5 sec.

5 Sn 0.4 291 Cu 0.3 Ni 0.5 0.4 300 C
x 5 sec.
1) 0. 6 Sn 0.4 291 Cu 0.3 Ni 0.5 0.4 E
mt 7 Sn 1.0 728 Cu 0.5 0.4 300 C x 5 sec.
x =LI 8 Sn 1.0 728 ___-ÑI 1.0 0.9 300 C x 5 sec.
I.) a' 9 Sn 0.3 218 Ag 0.3 315 Ni 1.0 0.9 None Vz 10 Sn 0.3 218 Ag 0.001 1.1 Ni 1.0 0.9 None a 11 , Sn 0.2 146 Ag 0.5 525 Ni 1.0 0.9 None u 12 Sn 0.2 146 Ag .../1_,....------ Ni 1.0 0.9 None 13 Sn 0.002 1.5 Ag 0.5 525 Ni 1.0 0.9 None 14 Sn 0.002 1.5 Ag ...õ..-----1,------- Ni 1.0 0.9 None 15 Sn 0.001 0.7 Ag 0.3 315 Ni 1.0 0.9 None 16 Sn 0.001 0.7 Ag 0.001 1.1 Ni 1.0 0.9 None 17 Ag 0.03 32 Sn 0.03 22 Ni 1.0 0.9 None Target 0.002_ 1_. 0.001 1. 0.005 0.03 __0.2 150 if;1.3 330 [0097]

[Table 10]
Heat Whisker Inserting Force Gas Corrosion Resistance Resistance Number Sulfurous Hydrogen NumberSalt Spray of Maximum Acid Gas Sulfide of Whiskers Whiskers Inserting Contact Generation of Force/Maximum Resistance Contact Situation of 20 gm Shorter Inserting Force Resistance Contact Contact Contact of Powder Than 20 or of Comparative Resistance Resistance Resistance Longer in gm in Length Example 1 Length [Number] [Number] [ /0] [inf2] [m2] [mc2] [m(2] [m_Q]
1 0 0 82 1-3 1-4 1-4 1-4 1-4 Average 2 0 0 79 1-3 6-9 1-4 1-4 1-4 Average 3 0 0 77 1-3 1-4 1-4 1-4 1-4 Good 4 0 0 79 1-3 1-4 4-7 5-8 6-9 Average 0 0 76 1-3 6-9 4-7 5-8 6-9 Good 6 0 0 77 1-3 1-4 1-4 1-4 1-4 Good 7 0 0 77 1-3 1-4 1-4 1-4 1-4 Good 8 0 0 77 1-3 1-4 1-4 1-4 1-4 Good 9 0 0 77 1-3 1-4 1-4 1-4 1-4 Good 0 0 77 1-3 1-4 1-4 1-4 1-4 Good 11 0 0 77 1-3 1-4 1-4 1-4 1-4 Good 12 0 0 77 1-3 1-4 1-4 1-4 1-4 Good 13 0 0 77 1-3 1-4 1-4 1-4 1-4 Good 14 0 0 77 1-3 1-4 1-4 1-4 1-4 Good 0 0 77 1-3 1-4 1-4 1-4 1-4 Good 16 0 0 77 1-3 1-4 1-4 1-4 1-4 Good 17 0 0 77 1-3 1-4 1-4 1-4 1-4 Good 18 0 0 77 1-3 1-4 1-4 1-4 1-4 Good .,, 19 0 0 77 1-3 1-4 1-4 1-4 1-4 Good g 20 0 0 77 1-3 1-4 1-4 1-4 1-4 Good LI 21 0 0 77 1-3 1-4 1-4 1-4 1-4 Good 22 0 0 77 1-3 1-4 1-4 1-4 1-4 Good 23 0 0 77 1-3 1-4 1-4 1-4 1-4 Good 24 0 0 77 1-3 1-4 1-4 1-4 1-4 Good 0 0 77 1-3 1-4 1-4 1-4 1-4 Good 26 0 0 77 1-3 1-4 1-4 1-4 1-4 Good 27 0 0 77 1-3 1-4 1-4 1-4 1-4 Good 28 0 0 77 1-3 1-4 1-4 1-4 1-4 Good 29 0 0 77 1-3 1-4 1-4 1-4 1-4 Good 0 0 77 1-3 1-4 1-4 1-4 1-4 Good 31 0 0 77 1-3 1-4 1-4 1-4 1-4 Good 32 0 0 77 1-3 1-4 1-4 1-4 1-4 Good 33 0 0 77 1-3 1-4 1-4 1-4 1-4 Good 34 0 0 77 1-3 1-4 1-4 1-4 1-4 Good 0 0 77 1-3 1-4 1-4 1-4 1-4 Good 36 0 0 77 1-3 1-4 1-4 1-4 1-4 Good 37 0 0 77 1-3 1-4 1-4 1-4 1-4 Good 38 0 0 77 1-3 1-4 1-4 1-4 1-4 Good 39 0 0 77 1-3 1-4 1-4 1-4 1-4 Good Average Target .,,,- 0 <85 _10 10 .10 _10 ..10 or higher [0098]

[Table 11]
Heat Whisker Inserting Force Gas Corrosion Resistance Resistance Number Sulfurous Hydrogen Number Salt Spray of Maximum Acid Gas Sulfide of Whiskers Whiskers Inserting Contact Generation of Force/Maximum Resistance Contact Situation of 20 gm Shorter Inserting Force Resistance Contact Contact Contact of Powder Than 20 orof Comparative Resistance Resistance Resistance Ilm in Longer in Example 1 Length Length [Number] [Number] [ /01 [m12] [m] [mû1 [mû] [m.Q]
40 0 0 77 1-3 1-4 1-4 1-4 1-4 Good 41 0 0 7'7 1-3 1-4 1-4 1-4 1-4 Good 42 0 0 77 1-3 1-4 1-4 1-4 1-4 Good 43 0 0 77 1-3 1-4 1-4 1-4 1-4 Good 44 0 0 77 1-3 1-4 1-4 1-4 1-4 Good - 45 0 0 77 1-3 1-4 1-4 1-4 1-4 Good g 46 0 0 77 1-3 1-4 1-4 1-4 1-4 Good 47 0 0 77 1-3 1-4 1-4 1-4 1-4 Good 48 0 0 77 1-3 1-4 1-4 1-4 1-4 Good 49 0 0 77 1-3 1-4 1-4 1-4 1-4 Good 50 0 0 77 1-3 1-4 1-4 1-4 1-4 Good 51 0 0 77 1-3 1-4 1-4 1-4 1-4 Good 52 0 0 77 1-3 1-4 1-4 1-4 1-4 Good - - - 1-3 3-7 1-3 1-3 1-3 Poor 2 ...----- .___---------- 1-3__------_______________________-----___ ..
Poor 3 -------- .3 120 1-3 Poor 4 -------' _3 90 1-3 3-7 1-3 1-3 1-3 Poor ...------"' __---------- 1-3 .---------______________--- ___------' Poor cl. 6 ____------- .2 105 1-3 .___.-------' ___.-------- Poor E
0 7 - - - -3 100 1-3 3-7 1-3 1-3 1-3 Poor x w 8 - - - ._3 100 1-3 3-7 1-3 1-3 1-3 Poor o a. 9 1-5 0 84 1-3 .------ Poor r*
.- 10 1-5 = 0 81 1-3 ____--------Average 11 ___________ 1-3 ___...--------Poor o c...) 12 1-3 10< --.01111111111111.1.¨ Average 13_ ¨ .1 i i I I i II I I I II I I 1.1%ii 111 I I I 1111111111 M: BM li I I I
I 111. " ¨I I il I Ill I I I I I I . " --- . . = id I I i I I 111 I II I ilw "
--I i I I I 111111 I I. " ¨ Poor 14_idaPPI101111111.11...-- 1-3 10< Good 15__./11111.1111Pw-1 II IIII III M
MINIPPIIIIMIIIIIIIII.¨IIIII 10< Avera le 16 ¨.0111011111 10< Good 17 _..,migIIIPPIIII""¨_õIIIIIIIIIIIIIIIIF3MIIIIII'w¨ __.------ _ ¨ 10<
Good Average Target 0 <85 __10 10 10 10 .10 or hi: er [0099]

[Table 12]
Heat Heat A Layer B Layer C Layer Inserting Force Gas Corrosion Resistance Treatment Resistance Maximum Sulfurous Hydrogen m Salt Spray (11 0 i-, 0 ,f, 0 4-= 0 VI 0 Inserting Contact Acid Gas Sulfide Generation S =
..
.3 u '-=' S .3 0 =,t g .2 Force/Maximum Resistance Contact - ..g .7) 0 - 5 .72 0 '''' ':
= Situation . .
J 0 u 0 O. :2 8-1 a 4 ,,,... , 4 Inserting Force =
Resistance Contact Contact Contact of Powder 0J1 5 A 0 of Comparative u Resistance Resistance Resistance (..) c..) c) Example 1 .
B-urli 411/01121_ Blip] 14=21_ [pm] Img/cm21 _ roi _ Imq Im01 [rnS2.1 _ [mai ttnC21 53 Sn 0.03 22 = Ag 0.03 32 Cr 1.0 0.9 None 66 1-3 1-4 1-4 1-4 1-4 Good _ _ _ . _ 54 Sn 0.03 22 Ag_ , 0.03 32 _ Mn 1.0 0.9 None 80 1-3 1-4 1-4 1-4 1-4 Good _.4 55 Sn 0.03 22 _ Ag_ _0.03 32 _ Fe 1.0 0.9 None _ 77 1-3 1-4 1-4 1-4 1-4 Good _ _ _ 56 Sn 0.03 22 Ag _0.03 32 _ Co 1.0 0.9 , None _ 75 1-3 1-4 1-4 1-4 1-4 Good _ P
57 Sn 0.03 22 _ A& _ 0.03 , 32 =Cu _ 1.0 . 0.9 None _ 79 1-3 1-4 1-4 1-4 1-4 Good _ .
58 Sn 0.03 22 A& _ 0.03 32 Ni-Cr 1.0 , 0.9 None _ 71 1-3 1-4 1-41-4 1-4 Good _ "
.3 i, 59 Sn 0.03 22 , Ag 0.03 _ 32 Ni-Mn _ 1.0 _ 0.9 None _ 79 1-3 1-4 1-4 _ 1-4 1-4 Good O
_ 60 Sn 0.03 _ 22 Ag _ 0.03 32 Ni-Fe 1.0 _ 0.9 None 77 1-3 1-4 1-4 , 1-4 1-4 Good .
u, w 61 Sn 0.03 22 Ag _ 0.03 32 Ni-Co 1.0 0.9 None _ 73 1-3 1-4 1-4 , 1-4 1-4 Goodo i-62 Sn 0.03 22 Ag _ 0.03 32 Ni-Cu 1.0 0.9 , None _ 77 1-3 , 1-4 ,. 1-4 _ 1-4 1-4 Good .
, 63 Sn 0.03 22 Ag _ 0.03 32 Ni-B 1.0 0.9 None _ 66 1-3 1-4 1-4 1-4 1-4 Good .
...]
, 64 Sn 0.03 22 Ag _ 0.03 32 Ni-P 1.0 0.9 _ None 66 1-3 1-4 1-4 1-4 1-4 Good u i-65 Sn 0.03 22 Ag , 0.03 32 Ni-Sn 1.0 0.9 _ None 75 1-3 1-4 1-4 1-4 1-4 Good _ 66 Sn 0.03 22 _ Ag _ 0.03 32 Ni-Zn 1.0 0.9 _ None , 77 1-3 1-4 1-4 1-4 1-4 Good 67 Sn _ 0.03 22 Ag , 0.03 32 Ni 0.1 0.1 _ None 80 1-3 1-4 1-4 1-4 1-4 , Good ,>) ,,,, 18 Sn 0.03 22 Ag 0.03 32 Ni 0.01 0.01 None 89 1-3 10< 2-4 2-4 2-4 cj w _ -0.0025_ 15. 0.0015 15 Average Target 0.0055 0.035 <85 510 _510 510 _510 510 _ 50.2 _5150 50.3 <330 -_ or higher [ 0 1 0 0 ]

[Table 13]
Heat A Layer B Layer C Layer Treatment Inserting Force Maximum Vickers Indentation Inserting Deposition Deposition Deposition Hardness Hardness Force/Maximum Bending Thickness Thickness Thickness Composition Amount Composition Amount Composition Amount Condition Inserting Force of Workability Comparative Example I
[lm] ille/cnizi IlAlui . [Kgieni2I _ [gm]
[mg/cm2] I lv [MPal ]%1 1 Sn 0.2 146 Ag 0.3 315 Ni 1.0 0.9 None 130 1500 82 Good u Ni (semi-68 Sn 0.2 146 Ag 0.3 315 bright) 1.0 0.9 None 300 3400 78 Good , 2 69 Sn 0.2 146 Ag 0.3 315 Ni (bright) 1.0 0.9 _ None 600 6700 72 Good P
.
64 Sn 0.2 146 Ag 0.3 315 Ni-P 1.0 0.9 None _ 66 Poor 0.002. V 0.001. l<
L.
Target 0.005_ 0.03.
<85 u, .A.2 _ =_150 _ Ø3 .330 r., .

, .
, , [010 1]
L.

[Table 14]
Heat Evaluation from Outermost Heat A Layer B Layer C Layer Gas Corrosion Resistance Treatment Surface Layer Resistance = . = .... = r.
. Arithmetic Maximum Contact Sulfurous Hydrogen o :?.,µ S .2 I t' 1 E I t ' o Average Salt Spray .h) 2 Height Resistance Contact Acid Gas Sulfide 8 .7, 0 =- ,g .7 0 :,...
Height Reflection g. 2 cct. c., in.', g .2 o e .-5 Density Resistance Contact Contact Contact .g CI 5 g 62 g 6' g c . . ) Ra Rz Resistance Resistance Resistance u u u fliml ktglem21 [pmf jug/cm21 , [j.unj [mg/cm2]
bun.] illmf [mS2] [mS2.1 [mai I ma] I mS21 1 Sn 0.2 (Dk=0.5) 146 Ag 0.3 (Dk=0.5) 315 Ni 1.0 0.9 None 0.12 1.25 0.2 1-3 2-4 2-4 2-4 2-4 _ a, 70 Sn 0.2 (Dk=0.5) 146 Ag 0.3 (Dk=4) 315 Ni 1.0 0.9 None 0.087 0.75 0.3 1-3 2-4 1-3 1-3 1-3 g _ x 71 Sn 0.2 (Dk=4) 146 Ag 0.3 (Dk=0.5) 315 Ni 1.0 0.9 None 0.075 0.55 0.7 1-3 2-4 1-3 1-3 1-3 P
w - -.
72 Sn 0.2 (Dk=4) 146 Ag 0.3 (Dk=45) 315 Ni 1.0 0.9 None 0.045 0.35 0.9 1-3 2-4 1-3 1-3 1-3 0.0025_ 15 0.0015_ l< u, Target 0.0055 0.035 510 510 510 _510 510 u, _50.2 5150 50.3 5330 N, .

, .
...]
, L.

[0102]
, [Table 15]
Heat Ileat A Layer B Layer C Layer Treatmen XI'S (Depth) Inserting Force Resistanc Gas Corrosion Resistance t e Maximum Salt Spray Sulfurous Hydrogen Contact Inserting Resistanc Acid Gas Sulfide cn 0 4-4 cn 0 i=-= Z r4 = =`11 Force/Maximu Contact I" :21 g 1 1.) :21 .2 l .tt g =
Thicknes e 1 .2 µg,. .771 .2 g, 5 ' .2 / 2 :-,-- Order of Di Di D2 s of 25% m Inserting Resistanc Contact Contact Contact rs.
D2, and D3 , or More Force of e Resistanc Resistanc Resistanc E E
! o Comparative e e e o o U
_______________ U _________________________________________________ Example I
h_tg/cm2 [mg/cm2 [at% [at%
[gm] [ggilem2 [gm]
1 [timl A [nrn] [%i [mS2] imS21 imi21 Im521 [mS2]
, IDI D2D -P
3 Sn 0.03 22 0.03 32 Ni 1.0 0.9 None =

35 35 100( 77 t) g , 3 o Iv 14 ,6.11 Sn 0.03 22 A
0.03 32 Ni 0.1 0.1 None Di :==D2=[) l-3 1-4 1-4 1-4 1-4 .
,..
u, c.L ' g 3 _ o ul Iv o r o.

Sn 0.03 22 A 0.03 32 Ni 0.01 0.01 None DiD2. D 87 87 25 89 1-3 <10 2-4 2-4 2-4 o 8 g 3 -J
, Q) Lo ..?.; 0 l A
*al ^ 0.03 22 Sn 0.03 32 Ni 1.0 0.89 None D2DiD

<10 ra 7g 3 r )/1 ni Sn 0.002 1.5 Ni 1.0 0.89 None Di D3 12 <10 100< 1-3 _--------- <10 u ' 1 A 1.)1D21) Sn 0.001 0.7 0.001 1.1 Ni 1.0 0.89 None <10 14 100<
.--------- 1-3 --- - - _ 0.002 0.
l< 001 l< 0.005 Target < < 0.03 <85 5_10 .10 5,10 5.10 <150 .330 <
..Ø2 [ 0103 ]

[Table 16]
Heat Heat A Layer B Layer C Layer Treatment Resistance Whisker Inserting Force Gas Corrosion Resistance Number Sulfurous Hydrogen of Number of Maximum Salt Spray Acid -as Sulfide --: Whiskers Whiskers Inserting Contact Generation g .., o -tc . ... ..: 0 g ¨ s 0 ...., g = ,^. i g 'f:1 of Shorter pm of 20 Force/Maximum Resistance Contact Situation ¨
.o u :2 g . .9 .9, 0 - o Inserting Force Resistance Contact Contact Contact of Powder cl, ra. .-.
' -'6 = or 4 g g g g .r8 o Than 20 of Comparative c.) ; Longer in Resistance Resistance Resistance (..) a. t...) CN g.
CS) g.
o i: "tin `11 Length Length _ - Example 1 c.
, 11-1m1 [1-18/0112L _ 1/1rIal illgien121_ i}-tml tingiern2i INumberl [Number] [0/.1 1mS11 _ linS21 IMS2.1_ _ ImS21 ImC21 , 3 Sn 0.03 22 Ag 0.03 32 Ni_ 1.0 0.9 None _ 0 o 77 1-3 1-4 1-4 1-4 1-4 Good _ --g, 73 Sn 0.01 7 Ag 0.03 32 _Ni_ 1.0 0.9 None _ 0 o 75 1-3 _ 1-4 1-4 _ 1-4 1-4 Good 74 Sn 0.005 _ 4 -Ag, 0.03 , 32 _Ni_ 1.0 0.9 None _ 0 o 74 1-3 , 1-4 2-6 _ 3-7 , 4-7 Good P
.
75 Sn 0.1 73 -AI_ 0.03 32 Ni 1.0 _ 0.9 None _ 0 o 79 1-3 = 1-4 1-4 .. 1-4_ .. 1-4 .. Good .. "
o, 76 Sn 0.2 - 146 ¨Ag 0.03 - 32 Ni 1.0 _ 0.9 None _ 0 0 83 1-3 1-4 1-4 1-4 1-4 Average .
L.
_ u, 0.0025 15_ 0.0015. 1 Average 0 u, Target 0.005 0.035 -' 0 <85 .10 1() _10 5.. 1 0 _. 10 <0.2 5.150 5_0.3 5330 or higher "

_ , .., , L.

[0104]

[Table 17]
Heat 1 teat A Layer B Layer C Layer Treatment Resistance Inserting Force Gas Corrosion Resistance ¨
Maximum Sulfurous Hydrogen cn 0 -..., = (A C.
r.f) 0 ..t Inserting Contact Salt Spray Acid Gas Sulfide Generation .9. ...0 ..= S .2 ''' ..'=. g .3 ¨ 5 0 Situation .- A .,45,., e .9 Force/Maximum Resistance Contact .+.4 ,-Q '7, "-.
[A
of Powder O = 0 o o`' -c, Inserting Force Resistance Contact Contact Contact o.
4`) k:'.. g a < 0 of Comparative c..) Resistance Resistance Resistance U __________ U Example 1 Binli il1e/ern2l_ , lurni ktg/cm21 _ B-tmi Lmeicm2i _ roi [in.Q] [mS21 _ [mc21 [mS2] ImS11 _ 3 Sn 0.03 22 Ag 0.03 32 Ni 1.0 0.9 None 77 1-3 1-4 1-4 1-4 1-4 Good . . , 1., 77 Sn 0.03 , 22 Ag 0.001 1.1 Ni 1.0 0.89 None 73 1-3 6-9 1-4 1-4 1-4 Good ¨ _ , 78_ Sn 0.03 22 Ag 0.007 7.4 Ni 1.0 0.89 None 74 1-3 2-5 1-4 1-4 1-4 Good T
_ _ - -79 Sn 0.03 22 Ag 0.1 105 Ni 1.0 0.89 None 78 1-3 1-4 1-4 1-4 1-4 Good Q
. _ _ _ _ 86 Sn 0.03 22 Ag _ 0.3 315 Ni _ 1.0 0.89 None 84 1-3 1-3 1-4 1-4 1-4 Average 0 r., _ _ .3 0.002..<. I. 0.001.
Average .
Target 0.005. 0.03_ <85 _10 _.10 .10 .10 5_ 10 L.
ul _0.2 150 _ ..<1.3 :030 or higher .
¨
1 u, r., .

..
, .
...]
[0105]
, L.
, [Table 18]
t leat A Layer B Layer C Layer Inserting Force Treatment Vickers Hardness Indentation Hardness Maximum Inserting Fi S +g 7A o .S
_ E
= .
Force/Maximum Generation ,... =
zn' o =
.2 .

.F.:. S
. cn o Correlation between Correlation between .g .x a E .2 .- .2 =V; C.) a E ' a Inserting Force of Situation .,6- .2 Vickers Hardness and Indentation Hardness 'a. ..
, h' a ...-E- 1, <
n . .4 =
E- 0¾
m g f lv Expression IMPa] and Expression Condition Comparative of Powder E __________________ E E
____________________________________________________ Example 1 o o o Expression: -376.22Ln Expression: -3998.4Ln Bun]I Illgicln2l [pm] lfleicln2l [um] [mg/cm2]
(thickness) + 86.411 (thickness) + 1178.9 IN
_ - 86.4 1178.9 .
3 Sn 0.03 22 Ag 0.03 32 Ni 1.0 0.9 130 =Vickers 1500 =lndentation None 77 Good Hardness?..Expression Hardness.Expression 86.4 1178.9 Ni (semi-81 Sn 0.03 22 Ag 0.03 32 1.0 0.9 300 Vickers 3400 Indentation None 74 Good bright) P
d Harness?..Expression Hardness.Expression , o _ 86.4 1178.9 o 82 Sn 0.03 22 Ag 0.03 32 Ni (bright) 1.0 0.9 500 =Vickers 5500 =1ndentationNone 70 Good o ,., u, HardnessaExpression Hardness?.Expression 0 .
u, 86.4 1178.9 1., o 64 Sn 0.03 22 Ag 0.03 32 Ni-P 1.0 0,9 1200 =Vickers 13000 =lndentation None 66 Good 1-Ø
, ' ...1 I

Ilardness1.LEx4pression liardnes2s:1x1pression Ni (semi- ,., o 83 Sn 0.03 22 Ag 0.03 32 0.8 0.7 300 Vickers 3400 Indentation None 75 Good -E. bright) Hardness_Expression HardnessExpression E

x 347.2 3950.4 Ni(semi -.
w i i 84 Sn 0.03 22 Ag 0.03 32 0.5 0.4 300 =Vickers 3400 =tndentation None 79 Good bright) Hardness<Expression flardness<Expression , 278.6 3221.4 85 Sn 0.03 22 Ag 0.03 32 Ni (bright) 0.6 0.5 500 =Vickers 5500 =lndentation None 76 Good Hardness?_Expression Hardness?.Expression . ' . _ 539.4 5992.9 86 Sn 0.03 22 Ag 0.03 32 Ni (bright) 0.3 0.3 500 =Vickers 5500 =lndentation None 81 Good _ fiardness<Expression Hardness<Expression _ . -691.9 7614.1 87 Sn 0.03 22 Ag 0.03 32 Ni-P 0.2 0.2 1200 =Vickers 13000 =4ndentation None 76 Good Hardness?.Expression HardnessExpression _ _ 1213.5 13157.0 .
88 Sn 0.03 22 Ag 0.03 32 Ni-P 0.05 0.04 1200 =Vickers 13000 =Indentation None 83 Good Hardness<Expression _ Hardness<Expression , _ - -0.0025 15. 0,0015. 15.
Average Target 0.005<
0.035 <85 50.2 .5150 50.3 5330-or higher [0106]
[Table 19]
Heat A Layer B Layer C
Layer Treatment Deposition Deposition Deposition Vickers Indentation Bending Thickness Thickness Thickness Composition Amount Composition Amount Composition Amount Hardness Ifardness Condition Workability [ptm] 11.1g/cm21 _ [pm] hig/cm21 [pm] [mg/cm2] Hv [MPa]
3 Sn 0.03 22 Ag 0.03 32 Ni 1.0 0.9 130 1500 None Good -al 9, 81 Sn 0.03 22 Ag 0.03 32 Ni (semi-bright) 1.0 0.9 300 3400 None Good _ x 82 Sn 0.03 22 Ag 0.03 32 Ni (bright) 1.0 0.9 600 6700 None Good w P
64 Sn 0.03 22 Ag 0.03 32 Ni-P 1.0 0.9 1200 13000 None Poor 0 r., .3 0.0025. l< 0.001 l<
0.005 0.03 u, Target 1:).2 =150 .Ø3 330 u, N, .

, .
, , [0107]
L.
, [Table 20]
Heat Heat A Layer B Layer C Layer Treatment Resistance XPS
(Depth) XPS (Survey) Gas Corrosion Resistance Thickness ofuS lfurous Hydrogen (Region) Salt Spray I 1 i Having a Concentration Acid Gas Sulfide = n e = rrp, e = v, .,9 .2 4.) < .2 ,.,cu < .2 (1) Z Concentration Concentration of Ag, Au, Pt, Concentration Contact .4,.. ,..Q
-2 = .c) o of Ag, Au, Pt, of Sn, In of Pd, Ru, Rh, of 0 of Resistance Contact `..61 2 .0 8 c) .2 µ4 o . ?. 15 Pd, Ru, Rh, Outermost Os, Ir of Outermost Resistance Contact Contact Contact - ra. ".: ....1 O

.
o" '71j e - E 8 O
o Os, Ir of 40 Surface Outermost Surface Resistance Resistance Resistance at% or higher Surface A A A) between Di and D3 [1-1M] Ellg/CM21 Eillni EggieM21 1.11M1 [Ing,km2] [nm]
[at] [at%[ [at%[ [mû] [mû] I ma] [mû] [m51] P
.
N, 3 Sn 0.03 22 Ag 0.03 32 Ni 1.0 0.9 None 30 7.3 2.6 24.1 1-3 1-4 1-4 1-4 1-4 0 4) L.

77 Sn 0.03 22 Ag 0.001 1.1 Ni 1.0 0.9 None 1 7.4 2.1 25.1 1-3 3-6 1-4 1-4 1-4 r.) t 0) _ -.3 ri 5 Sn 0.002 2 Ag 0.001 1.1 Ni 1.0 0.9 None 1 3.4 2.5 35.1 1-3 3-6 4-7 5-8 6-9 t L.

w _ 89 Sn 0.03 22 Ag 0.03 32 Ni 1.0 0.9 30 4.1 1.7 38.2 1-3 1-4 1-4 1-4 1-4 x 5 sec. _ 90 Sn 0.03 22 Ag 0.03 32 Ni 1.0 0.9 30 2.2 1.2 57.1 3-5 3-6 3-5 3-5 3-5 x 20 sec.
4) 16 Sn 0.001 0.7 Ag 0.001 1.1 Ni 1.0 0.9 None 1 1.2 2.5 24.1 1-3 7/ <10 E
0 [4 19 Sn 0.03 22 Ni 1.0 0.9 None 7.3 25.1 1-3 <10 Z,7 (-) , 0.002. 15_ 0.001 1... -Target 0.005_ 0.03. .10 5_ I 0 _. 1 0 I0 _C. 10 ..Ø2 ..150 :0.3 .330 [0108]

¨ 69 ¨
[Table 21]
, , Ileat Heat A Layer B Layer C Layer Treatment Resistance Inserting Force Gas Corrosion Resistance Maximum Sulfurous Hydrogen 0 .-. n 19 o n , 0 ,T, n Inserting Contact Salt Spray Acid Gas Sulfide Generation .2 6 .o 0 .2 a) .4 S .2 4) ...S *g.
0 Resistance Situation .-:-.. 5 =,7, g ..,4 5 .76; 0 .o. .2 .7, . .9, Force/Maximum Contact ,k' ..-'-' of Powder - Inserting Force of Resistance Contact Contact Contact P. .., g 4 ca O g & O & 0 c.) Comparative Resistance Resistance Resistance (...) (..) (...) Example 1 111m1 II-Le/ern21 _ II-unl II-Igtern21 [41n1 _ [mg/cm2]
¨ 1%1 Imol 1m01 Imi21 InI01 Imal Ag-91 Sn 0.03 22 0.03 32 Ni 1.0 0.9 None 78 1-3 1-4 1-4 1-4 1-4 Good 10Sn .
Ag-4., 92 Sn 0.03 22 0.03 32 Ni 1.0 0.9 None 77 1-3 1-4 1-4 1-4 1-4 Good P
40Sn ._ .
; 93 Sri-0.03 22 Ag 0.03 32 Ni 1.0 0.9 None 75 1-3 1-4 1-4 1-4 1-4 Good "
,.., Ag5 L.
u, _ Sn-u, 94 0.03 22 Ag 0.03 32 Ni 1.0 0.9 None 72 1-3 1-4 1 -4 1-4 1-4 Good Ag40 N, .

- , _ ¨ _ __ , , 0.002_5 1_5 0.0015 l5Average ' ...]
Target 0.0055 0.035 <85 510 _510 5 1 0 510 5 1 0 1 50.2 5150 50.3 , 5330 , I
or higher L.

[0109]

[Table 22]
Heat Heat A Layer B Layer C Layer Treatment Resistance Inserting Force Gas Corrosion Resistance Maximum Inserting Contact Sulfurous Hydrogen -3 t' .2 <, .E. 1 0 Force/Maximum Resistance Salt Spray Acid Gas Sulfide ' EA 0 =V; 2 %-= Inserting Force of Contact F61; 4 o el o O .L...) P cS..
6" ______________________________________ I 4 il..., 6' .
.=E3 0 Example 1 c...) Comparative E
Resistance Contact Contact Contact Resistance Resistance Resistance (..) BABA illgicm2i B-Lmi [118/cm2i [um] [mg/cm2] _ Mi [mS2] [m(1] [mS)] [mS)] Imill 95 Sn 0.03 22 Ag 0.03 32 Ni 1.0 0.9 None 77 1-3 96 Sn 0.03 22 Ag 0.03 32 Ni 1.0 0.9 76 1-3 1-4 x 12h 97 Sn 0.03 22 Ag 0.03 32 Ni 1.0 0.9 73 1-3 1-4 1-4 1-4 1-4 .
x 12h "
.3 cl) 50 C
,..
eta, 98 Sn 0.03 22 Ag 0.03 32 Ni 1.0 0.9 72 3-5 3-7 1-4 1-4 1-4 u, .
>1 x 20h o u, w 99 Sn 0.03 22 Ag 0.03 32 Ni 1.0 0.9 73 1-3 1-4 1-4 1-4 1-4 1-x 3 sec.
.

.

...]
100 Sn 0.03 22 Ag 0.03 32 Ni 1.0 0.9 72 1-3 1-4 1-4 1-4 1-4 ' L.
x 1 sec.

101 Sn 0.03 22 Ag 0.03 32 Ni 1.0 0.9 73 x 1 sec.
_ 0.0025. 15 0.0015 15 Target 0.0055 0.035. <85 _510 510 5_ 1 0 ._ 1 0 10 50.2 5150 _50.3 5330 [0110]
Examples 1 to 101 were press-fit terminals, which had the excellent whisker resistance and the low inserting force, were unlikely to cause shaving of plating when the press-fit terminal was inserted into the substrate, and had the high heat resistance.
Comparative Example 1 is a blank material.
Comparative Example 2 was fabricated by making thin the Sn plating of the blank material of Comparative Example 1, but generated whiskers thereby to be poor in the whisker resistance.
Comparative Example 3 was fabricated by being subjected to no heat treatment, in comparison with Comparative Example 2, but generated whiskers thereby to be poor in the whisker resistance, and was higher in the inserting force than the target.
Comparative Example 4 was fabricated by carrying out Cu plating for the C layer, in comparison with Comparative Example 2, but had the inserting force of 90%
of Comparative Example 1, which was higher than the target, and was poor in the heat resistance.
Comparative Example 5 was fabricated by making the Sn plating thin, in comparison with Comparative Example 4, but generated whiskers thereby to be poor in the whisker resistance.
Comparative Example 6 was fabricated by being subjected to no heat treatment, in comparison with Comparative Example 5, but generated whiskers thereby to be poor in the whisker resistance, and was higher in the inserting force than the target.
Comparative Example 7 was fabricated by being subjected to Cu plating for the C layer, in comparison with the blank material of Comparative Example 1, but exhibited no variations in the properties in comparison with Comparative Example 1.
Comparative Example 8 was fabricated by making the Ni plating of the C layer thick in comparison with the blank material of Comparative Example 1, but exhibited no variations in the properties in comparison with Comparative Example 1.
Comparative Example 9 was fabricated by making the Sn plating of the outermost surface layer thick in comparison with Example 1, but surely generated one or more whiskers of shorter than 20 gm though there was no whiskers of 20 gm or longer in length, which was the target.
Comparative Example 10 was fabricated by making the Ag plating of the B layer thin in comparison with Comparative Example 9, but surely generated one or more whiskers of shorter than 20 gm though there was no whisker of 20 gm or longer in length, which was the target.
Comparative Example 11 was fabricated by making the Ag plating of the B layer thick in comparison with Example 1, but provided a large amount of powder generated.
Comparative Example 12 was fabricated by carrying out no Ag plating of the B layer in comparison with Comparative Example 11, but was poor in the heat resistance.
Comparative Example 13 was fabricated by making the Ag plating of the B layer thick in comparison with Example 4, but provided a large amount of powder generated.
Comparative Example 14 was fabricated by carrying out no Ag plating of the B layer in comparison with Comparative Example 13, but was poor in the heat resistance.
Comparative Example 15 was fabricated by making the Sn plating of the A layer thin in comparison with Example 4, but was poor in the gas corrosion resistance, and higher in the contact resistance after the hydrogen sulfide gas corrosion test than the target.
Comparative Example 16 was fabricated by making the Sn plating of the A layer thin in comparison with Example 5, but had a maximum value of the atomic concentration (at%) of Sn or In of the A layer of 10 at% or lower in a depth measurement by XPS (X-ray photoelectron spectroscopy), was poor in the gas corrosion resistance, and higher in the contact resistance after the hydrogen sulfide gas corrosion test than the target.

Comparative Example 17 was fabricated by reversing the plating order of Sn and Ag in comparison with Example 3, but was poor in the gas corrosion resistance and higher in the contact resistance after the hydrogen sulfide gas corrosion test than the target, because in a depth measurement by XPS (X-ray photoelectron spectroscopy), the position (Di) where the atomic concentration (at%) of Sn or In of the A layer was the maximum value and the position (D2) where the atomic concentration (at%) of Ag, Au, Pt, Pd, Ru, Rh, Os, or Ir of the B layer was the maximum value were present in the order of D2 and Di.
Comparative Example 18 was fabricated by making the Ni plating thin in comparison with Example 3, but had the high inserting force, and was poor in the heat resistance, because in a depth measurement by XPS (X-ray photoelectron spectroscopy), a depth where the atomic concentration (at%) of Ni, Cr, Mn, Fe, Co, or Cu of the C
layer was 25 at% or higher was shallower than 50 nm.
Comparative Example 19 was poor in the heat resistance, because Sn of the A layer was thin, and the B
layer was not formed.
[0111]
Figure 2 shows a depth measurement result by XPS (X-ray photoelectron spectroscopy) in Example 3. It is clear from Figure 2 that the position (Di) where the atomic concentration (at%) of Sn or In of the A layer was the maximum value and the position (D2) where the atomic concentration (at%) of Ag, Au, Pt, Pd, Ru, Rh, Os, or Ir of the B layer was the maximum value were present in the order of Di and D2; and Di had 35 at%, and D2 had 87 at%.
Figure 3 shows a survey measurement result by XPS
(X-ray photoelectron spectroscopy) in Example 3. It is clear from Figure 3 that 0 was 24.1 at%; Ag was 2.6 at%;
and Sn was 7.3 at%.
[Reference Signs List]
[0112]
METAL MATERIAL FOR PRESS-FIT TERMINAL

Claims (14)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A press-fit terminal comprising:
a female terminal connection part provided at one side of an attached part to be attached to a housing; and a substrate connection part provided at the other side and attached to a substrate by press-fitting the substrate connection part into a through-hole formed in the substrate, wherein at least the substrate connection part has a surface structure comprising:
an A layer formed as an outermost surface layer and formed of Sn, In, or an alloy thereof;
a B layer formed below the A layer and comprising Ag, Au, Pt, Pd, Ru, Rh, Os, Ir or any combination thereof; and a C layer formed below the B layer and comprising Ni, Cr, Mn, Fe, Co, Cu or any combination thereof, wherein the A layer has a thickness of 0.002 to 0.1 µm, wherein the B layer has a thickness of 0.001 to 0.3 µm, and wherein the C layer has a thickness of 0.05 µm or larger.

2. A press-fit terminal comprising:
a female terminal connection part provided at one side of an attached part to be attached to a housing; and a substrate connection part provided at the other side and attached to a substrate by press-fitting the substrate connection part into a through-hole formed in the substrate, wherein at least the substrate connection part has a surface structure comprising;
an A layer formed as an outermost surface layer and formed of Sn, In, or an alloy thereof;
a B layer formed below the A layer and comprising: Ag, Au, Pt, Pd, Ru, Rh, Os, Ir or any combination thereof; and a C layer formed below the B layer and comprising Ni, Cr, Mn, Fe, Co, Cu or any combination thereof, wherein the A layer has a deposition amount of Sn, In of 1 to 150 µg/cm2, wherein the B layer has a deposition amount of Ag, Au, Pt, Pd, Ru, Rh, Os, Ir of 1 to 330 µg/cm2, and wherein the C layer has a deposition amount of Ni, Cr, Mn, Fe, Co, Cu of 0.03 mg/cm2 or larger.

3. The press-fit terminal according to claim 1 or 2, wherein the A layer has an alloy composition comprising 50 mass% or more of Sn, In, or a total of Sn and In, and other alloy component or components comprise Ag, As, Au, Bi, Cd, Co, Cr, Cu, Fe, In, Mn, Mo, Ni, Pb, Sb, Sn, W, Zn or any combination thereof.

4. The press-fit terminal according to any one of claims 1 to 3, wherein the B layer has an alloy composition comprising 50 mass% or more of Ag, Au, Pt, Pd, Ru, Rh, Os, Ir, or a total of Ag, Au, Pt, Pd, Ru, Rh, Os, and Ir, and other alloy component or components comprise Ag, Au, Bi, Cd, Co, Cu, Fe, In, Ir, Mn, Mo, Ni, Pb, Pd, Pt, Rh, Ru, Sb, Se, Sn, W, Tl, Zn or any combination thereof.

5. The press-fit terminal according to any one of claims 1 to 4, wherein the C layer has an alloy composition comprising 50 mass% or more of a total of Ni, Cr, Mn, Fe, Co, and Cu, and further comprising B, P, Sn, Zn or any combination thereof.

6. The press-fit terminal according to any one of claims 1 to 5, wherein the A layer has a surface indentation hardness of 1,000 MPa or higher.

7. The press-fit terminal according to any one of claims 1 to 6, wherein the A layer has a surface indentation hardness of 10,000 MPa or lower.

8. The press-fit terminal according to any one of claims 1 to 7, wherein when a depth analysis by XPS (X-ray photoelectron spectroscopy) is carried out, a position (DI) where an atomic concentration (at%) of Sn or In of the A
layer is a maximum value, a position (D2) where an atomic concentration (at%) of Ag, Au, Pt, Pd, Ru, Rh, Os, or Ir of the B layer is a maximum value, and a position (D3) where an atomic concentration (at%) of Ni, Cr, Mn, Fe, Co, or Cu of the C layer is a maximum value are present in the order of DI, D2, and D3 from the outermost surface.

9. The press-fit terminal according to any one of claims 1 to 8, wherein the A layer has a thickness of 0.01 to 0.1 µm.

10. The press-fit terminal according to any one of claims 1 to 9, wherein the A layer has a deposition amount of Sn, In of 7 to 75 µg/cm2.

11. The press-fit terminal according to any one of claims 1 to 10, wherein the B layer has a thickness of 0.005 to 0.1 µm.

12. The press-fit terminal according to any one of claims 1 to 11, wherein the B layer has a deposition amount of Ag, Au, Pt, Pd, Ru, Rh, Os, Ir of 4 to 120 µg/cm2.

13. The press-fit terminal according to any one of claims 1 to 12, wherein the press-fit terminal is fabricated by forming surface-treated layers on the substrate connection part in the order of the C layer, the B layer, and the A
layer by a surface treatment, and thereafter heat-treating the surface-treated layers.

14. An electronic component comprising a press-fit terminal as defined in any one of claims 1 to 13.